December 15, 2011 • 42 mins
Earthworms come in a wide range of sizes: The average U.S. earthworm is 6 to 11 inches long, and the giant worms of Australia and South America can grow to a length of 11 feet. Join Josh and Chuck as they burrow into the weird world of earthworms.
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Speaker 1 (00:00):
Brought to you by the reinvented two thousand twelve camera.
It's ready. Are you welcome to Stuff you should know
from House Stuff Works dot Com. Hey, and welcome to
the podcast. I'm Josh Clark. There's Charles W Chuck Bryant
and that makes his debut take two. Rarely do we
(00:25):
have a take two, very rarely, but we did today.
Yeah we did. We started just kind of talking and
shop and Jerry's like, what are you guys doing? Yea, um,
but anyway, here we are. We're back, We're happy, everything's
good and um we're we're gonna talk a little bit
about earthworms, right, Yes? Are you feeling good about this one?
(00:47):
I am very interesting stuff. I wrote this article specifically
so we can podcast on it. So, chuck y, have
you heard of a man named Charles Darwin? You know
I love Chuckie d So chuck Chuck the Charles Darwin
um very famous for the On the Origin of the
Species um incredibly important work. Did you know though, that
(01:12):
The Origin of the Species was out sold in the
nineteenth century by another book of his called The Formation
of Vegetable Mold through the Action of Worms, with observations
on their habits that sold more copies for real. Yeah,
through throughout the rest of the nineteenth century. It was
published in one UM and I think like the Origin
(01:33):
of the species came a little after that. So, but
just during the nineteenth century for a while there, um,
the formation of vegetable mold was crazy out selling on
the origin of the species. I saw today where he
studied earthworms for thirty nine years. Yeah, it was. This
book was very near and dear to his heart, like
(01:54):
this topic was. He spent a lot of time really
looking at earthworm. I guess he died because why would
you give up at thirty nine? I would say, let's
just make it an even forty. I think he wrote
the book and was like, Okay, don't you go. I'm done.
I'm onto some Let's go to Galapagos exactly you know,
um he uh. He came up with in this thirty
(02:16):
nine years and in this book some very um, very
well understood observations that are still accepted today. Right. Um.
As a matter of fact, we have a quote from
him as read by him. All right, you want to hear.
It may be doubted whether there are many other animals
which have played so important apart in the history of
(02:36):
the world, as have these lowly organized creatures. So there
you have it. Wow, the earthworm is very, very important.
I didn't know he talked like that. I didn't either.
It's kind of surprising, um, but he. Uh. This this idea,
this concept that the earthworm is extremely important to the
(02:57):
earth was kind of put forth by Darwins and accepted
as gospel since them and in the decades and centuries
since Darwin. He did such a good job that earthworm
research kind of fell by the wayside. Scientific community was classifying,
classifying as extinct, like worms they just hadn't seen in
a while that would just later pop back up, like
(03:19):
the giant pelouse earthworm in the Pacific northwest of the
United States. It was thought to be extinct, classified as
such in the eighties, and then in two thousen it
pops up and they're like, oh, it's not extinct. The
worm popped up. And that happens a lot with earthworms,
like people just classified him as extinct. So this kind
(03:40):
of like these appearances of kind of reinvigorated science and
it's inquiry into earthworms. I wonder how he got on it, Darwin. Yeah,
I mean out of all the different things he was studying.
I wonder how he honed in on the earthworm and
knew its value, just because if no one else had
studied its value, I would never look at an earthworm
and think it's very valid able at all. No, but
(04:01):
people before Darwin realized the value of earthworms like aristotles
of the soil. No, but he's the one who dedicated
thirty nine years to studying them. Um So just in
sheer size alone, um, I guess in sheer volume is
a better way to put it. Earthworms are there. They
(04:22):
have a substantial impact on earth. I think, so three
thousand species. Notice it didn't say species species. You know
people say species. Sorry species Germans know a lot of
people say species as species, species, species, species. I don't
(04:43):
know which one I say. I think both acceptable. I
think not species. Yeah. Uh. They have reigned in size
from about a centimeter to nine feet, although they go
away more than that. Yeah. I think the world record
I found was one in South Africa was twenty two
ft long. Twenty two ft long earthworm. That's huge, and
(05:03):
there are plenty others. Japan has some giant ones, Australia
does too. Of course, I found one. We'll talk about that.
Lots of giant freaks of nature. But here's here's the
cool stat of the day for me. Uh Plus, we
get to say the word hectare just close to two
and a half acres. Yeah, it's like two point four
seven single hecked air. You can find five hundred thousand
(05:23):
to two million worms, and their total biomass wet biomass
equals ten times a total weight of all the other
animals living above ground combined on that same size spot
of land, on that same heck there. Yeah, that's nutty.
That is nutty, especially considering that worms don't go that
deep into the soil. Let's say there's twelve deer on
(05:46):
that heck dare I mean, that's gonna be a lot
of weight right there. It's just from the deer. Say
say each deer weighs a hundred and fifty pounds, it's
like eight hundred pounds and a dozen deer some amount
of kilograms. Yeah, that's probably like n So the point
is a lot of worms. Yeah, there are, there's a
(06:06):
ton of worms. Um, they're spread all over the place.
But here's an interesting fact. If um, if you've read fourteen,
you probably already know this Charles Man's brilliant follow up
to his triumphant I can't wait for fo Yeah, look
out for that one. He's just gonna pick some random
(06:26):
date like um. If the if you go into uh,
the average North American woods in the northern United States,
say um, and you find an earthworm, that earthworm. Had
you dug in the same spot five hundred years before,
you wouldn't have found any earthworms there. Like all earthworms
(06:48):
in North America and Canada above about the forty degree
latitude UM are new. They're relatively recent immigrants from Asia
and Europe, and they hitched a ride thanks to the
coling to America in plants the soil. Yeah, root balls
that were attached to plants um that were imported to
the United States and Canada. UM from Asia and Europe. Yes, Chuck,
(07:13):
I have a question. Yes, I have a few questions
for you, because you wrote this and it's always nice
to speak to the author, and you're right in front
of me. So how's how's that I'm right here? Uh?
Do they know what was here before the ice age
that killed off all the original native species? Surely there
were worms. Then it's an excellent question. No, they don't know.
(07:34):
Now they know that, I guess not because it was
pretty ice age. It's not like they had records. There
were some there's there's fossil there's fossil records of earthworms
that go back like a hundred and sixty five million years,
like there was a huge giant earthworm that it was
armor plated. Right. But yeah, but the stuff in North America,
apparently the fossil record is fairly incomplete here. Um, they
(07:55):
do suspect that a lot of worms made their way
southward towards warmer ground when these glacial ice sheets started
bearing down from Canada. Everything, a lot of stuff died,
some stuff high tail it south. So you can bet
that if you go to southern California or Mexico and
big and find a worm, that's probably the same species
(08:17):
that were higher up, species that were further north, you know,
prior to the last because you make a point later
that it's considered an invasive species because it's not native.
But I thought, well, surely they weren't that different before
the ice age, right. Well, the species the species that
are here, especially um, the common European earthworm, which we
(08:39):
here in the United States called nightcrawlers. That's from Europe,
which is why it's the common European nightworm. Those are
recent immigrants. Those guys weren't here before, right. So the
other reason they're invasive, Chuck, is since the end of
the last ice Age, say ten to twenty thousand years ago,
these woodlands in the north in the United States, uh developed,
(09:02):
they adapted, they changed to life without earthworms. Now they're
having to adapt to life with earthworms. That makes sense,
which makes earthworms invasive. Now, yeah, I get that, that
makes perfect sense. All right. Well, hey, look at there.
We covered a bit at the end. Yeah, we're gonna
get out here early now thanks. Another cool point you
make is if you dig down into the earth in
(09:25):
your backyard, in the earth a couple of feet, you're
probably gonna find all three classifications of earthworm because they're
they're classified by where they live in the soil. Because
they're also similar in appearance. I mean, yeah, except for
like maybe how thick around they are, how many segments
they have, um, how long they are. That's pretty much
(09:45):
the differences in earthworms. They're all very similar like wherever
you are. But there are three classes. And like you said,
they're based on where they live, Like there's the ones
above ground. Yeah, I've been pronouncing in my head eyak,
but GX sounds a lot I like gay do you like? Guy?
Let's go with that. Well, because it's a it's derivative
(10:06):
of gaya earth and eppie is above. So this is this,
This is the classification of earthworms that live like in
the leaf litter, which is also called the litter horizon,
that pile of leaves and organic material that that covers
the soil that these red wigglers. Red worms have a
lot to do with the fact that it's you know,
(10:28):
eventually gonna be black and slimy. Yeah, almost all of
the fact all they have almost everything to do with that.
I mean there's other like microbes and protozoa and other
stuff like that breaking it down, but the worms are
the ones that can get it done. So those red
wigglers are fun to play with if you're a kid.
Uh so are the next level down you get to
the indo gaeic as we'll say. Now they live in
(10:49):
the top soil that sort of you know how deep
like the first several inches, Yeah, you know, like the
dark top soil. Good stuff. As I like to call it. Yeah,
and they spend their whole lit beneath the soil, which
is why they're usually like very light in color, gray pinkish,
they're white, kind of uglier. Yeah. Have you ever seen
that movie The Layer of the White Worm. That's a
(11:12):
great horror. Yeah, I've heard of Hugh Grants first movies.
Awesome was he the white Worm? No? He was the dude. Okay,
he played a man. Uh. You say because they live
under the soil full time, that the least amount of
information is known about them. But another question the next
(11:33):
level down that uh and and essek they hold the
nightcrawlers the deepest dwelling ones. But it seems like we
know more about them than the other guys, a little
pink and gray guys. So why would that be? Well,
the reason is is because the little pink and gray guys,
the epigaic ones um, spend their whole lives underground, so
(11:55):
they just stay there. Yes, okay, they also make horizontal burrows, right,
so like they don't have to come up at all.
They don't. They have almost nothing to do with leaf decomposition.
So the nightcrawlers come up and then go back down
exactly Not only do nightcrawlers come up, they come up
and travel as far as like sixty two ft in
a night looking for food. Like they hang out above ground.
(12:17):
The epigaic ones you have to dig down for them.
They're not coming up to greet you. So the scientists
don't have spades. That's what I'm saying, man Like the
like science generally was like, Okay, Darwin wrote the book
on earthworms. You don't have to any more investigation about that. Interesting.
Another cool fact about the nightcrawler is that they go
upstairs to to grab some food and bring it back down.
(12:41):
They're like, hey, that leaf is really choice and moist,
so I'm gonna grab it and take it back downstairs
and just chow. So my little belly bursts. I love that. Yeah,
but it also kind of gives you an idea of
like just how powerful like a nightcrawler is it drags
its food back to its house. You know. I used
to hate fishing with worms. That's that and the potential.
(13:07):
One time I went fishing and caught brim, and um,
I didn't have a hook remover and this thing, this
brim swallowed this hook like crazy, and I was trying
so hard to get it out, and it was just
like obvious that this weren't This fish was dying. And
one of his buddies was just sitting there almost at
the bank, almost up on the ground, watching me, just
(13:29):
looking at me like why did you do that? So
that and then the that she club that one, I
was like stopped looking at me. Fishing just punched the water.
Um that the potential of a fish dying, and then
the guarantee of worms dying, uh made me quit fishing
forever sticks because fish is fun. Fishing is fun. I
(13:50):
love to fish, yeah, but I just don't do it anymore.
All right, Well that's sad for you. Oh club fish
like clubbing, but I won't actually use like a roden reel.
Earthworms are segmented Josh, which is also very interesting. Uh.
They are from the phylum Annelid, which means ringed worm.
(14:12):
And there's about a hundred to a hundred and fifty
of these rings and they're each controlled separately little muscles,
which is very important because they expand and contract to
move their little slimy bodies forward. And they have these
bristles at the front towards the head the anterior and
um that are retractable. They're called settee, and um, they
can just go big and dig into the dirt and
(14:36):
hold the head in place while the rest of the
body kind of contracts to get smaller to move forward
like that. So these sete you go in and out
depending on whether the heads moving or is it needs
to be anchored so the rest of the body can
catch up. And that's how they scoot along at sixty
two per night for nightcrawlers. So um, pretty much, Chuck,
(15:00):
I don't know what we're naming this one yet, but
one of the one of them the suggestions you made
was earthworms eating and pooping machines kind of like sharks,
and I mean kind of um, but possibly even more
beneficial than sharks. Sharks are like an apex predator. Right
of course, earthworms are not an apex predator, but like
(15:21):
I said, Aristotle call him the intestine of the soil.
And one of the reasons why is because they just
eat and eat and eat, and the stuff that they
do eat they poop out. And it's actually what's crazy,
remember the digestion um episode, So like the stuff that
comes out of us, it's like nobody needs that. It's
(15:42):
total waste with the worm, it's actually better than it
was before. Warm poop is better than the food it eats. Yeah,
that's pretty cool. That is pretty cool. And the way
it eats is even cooler. I think. Um, they obviously
eat and you're not gonna be able to tell a
huge difference between the mouth end and the anus end
(16:04):
unless you really dig your fingers in there. But at
the mouth end, they're gonna they're gonna pass dirt and
organic matter into their mouth and it's gonna go into
an area called the crop where they store it for
a little while, then into the gizzard. And this is
the coolest part to me. In the gizzard, they have
these tiny pebbles that they've already eaten, and those pebbles
(16:25):
grind the food up even more like a little food
processor to make it easier to pass through. That is
so cool. And uh, in the intestinal walls, they they're
aligned with blood vessels and sort of like our own
blood vessels, they absorb and distribute nutrients. So it's not
that much different than people. Yeah, no, it's not the
thing about earthworms though, is the nutrients, especially nitrogen um,
(16:51):
that they eat that they pass out is about of
what was say, locked into a leaf, so they only
keep like a order of the available nitrogen for themselves.
But through digestion, what was once just locked into this
leaf and was totally unusable to like a tree root,
is now digested and broken up and available. It's called
(17:15):
nitrogen fixing. And that's what worms do. They're casting their
feces is broken down nitrogen, which is why people use
worms for composting. That's exactly right there, the secret ingredient.
While they're not secret but key ingredient to compost. But
that's the that's the epigayic right. The ones that live
(17:37):
above ground, the compost ones, the earthworms, like the annesic ones,
they're big into composting two but they do it below ground.
Um earthworm has five hearts. Kind of a neat fact
right there. I would say aortic arches and uh I
saw I think I saw in another photo like they
(17:57):
have one of the main ones is that and then
four other ones? Are they all equal? I think that
they are. There's a main one, I believe, so you
think I know you and chuck. The breathing through their
skin is another cool trait. They don't have lungs, but
they still need to breathe, so they just pass it
passively through the skin inhaling and exhaling. There's no inhaler
(18:22):
exhale because it just happens. But I call that an inhale.
Even though when I was writing this, I had to
go back. I was like, no, they're not inhaler. Yeah. Um,
as long as their skin is coated in this mucus
that they produced, that's how air exchanges is allowed to
take place. Um. And if there's enough broken down available
(18:43):
oxygen in a body of water, a worm can live
in water. It can survive in water for a while
because the air exchange is still taking place. They're just
grabing oxygen. Yeah. Um. The problem is is when they
encounter like really dry hot air like above ground. Yeah.
I think we've all seen that sad, sad site. Right.
So if you if you've ever seen like a worm
(19:05):
that's curled up and is dry on the sidewalk that
were suffocated to death because it wasn't able to breathe.
That's mucus dried out. I couldn't breathe, you know, and
all it needed to do is reach those leaves, but
it failed on the sidewalk and that happens a lot
in Georgia. Obviously you see a lot of those in
the summertime. Uh. And to to make sure that they survive.
(19:28):
They don't have eyes, so it's not like they can say, oh,
the sun's out, but they're able to sense light through
these photo sensitive cells on their skin that convert light
into electrical impulses. So they feel this and say, hey,
it's sunny out, I need to burrow down a little
bit more. Yeah, pretty cool, yep. And this is why
these buggers have survived for so long. It is. And um,
(19:50):
that's also the role for their brain that their brain
plays is to say, I'm sensing some light, so let's
move down a little for there where there's not light.
That's pretty much the extent of the worm brain. Yeah,
that's what I saw. They said, if you remove the brain,
then you're hardly going to notice any change in behavior,
(20:11):
except I guess they would dry up in the sun. Yeah. Right,
So maybe that's what we've seen is brainless worms on sidewalks. Yeah,
or maybe they lost part of it. Someone remove their brains.
We can go ahead and talk about that the regeneration. Okay,
go ahead, because I need some explanation on that part.
I get it a worm if if it's part of
(20:32):
it is chopped off somehow, Um, they can regenerate uh
more more towards the tail than the head. Is that right?
So like that if you cut a worm in half,
only one half is going to regenerate. Most likely it's
the head end that they have an easier time regenerating
their tail than they have their head. That makes sense. Um.
(20:53):
The thing is is one of the joys of this
is like anytime there's a question or something's vague, can
be like, yeah, science really dropped the ball on earthworm
research for a century. They there there's evidence that like
and both sides can regenerate into two new worms. People
have documented this supposedly, Um, there's like different, um, contrary
(21:17):
evidence about how much could regenerate or how little, like
how little of a segment you need to regenerate into
a new worm. So there's a bunch of apparently there's
a bunch of evidence out there that says like worms
are spectacular regenerating and others are saying they're a little
more limited than we think. Well, any kind of regeneration
is pretty amazing if you ask me, Yeah, I agree.
(21:37):
But if you want to make a bet with your friend,
a very cruel friend who had just cut a worm
directly in half, which end was going to regenerate, always
put your money on the tail end. I could never
I mean, it's just a little worm. I could never
do that because they just squirmed so much like they're
in horrible pain. You know. Yeah, have you read considered
the lobster David Foster Wallace, like his his article for
(22:01):
Gourmet magazine. Well, they sent him to like the Lobster Festival,
and we were just expecting like a kind of a
travel foodie article, and instead he went and did a
bunch of research on whether or not lobsters feel pain
because they're boiled to death. Yea, and definitely make noises
to when that happened. They do. They scratch like the
pot trying to get out. They do. But the key
(22:24):
is is like, yes, surely they feel pain. Of course
they feel pain. Um, they it's been shown that they
have nerve receptors that you know, since pain, do they
experience suffering? So that weren't squirming in in pain and
suffering or just pain and really doesn't matter, I mean,
and think inflicting pain on anything is cruel, but inflicting
(22:44):
suffering is evil. Yeah. Yeah, I don't need a much lobster.
Yeah you me um read that and was like, I'm
never eating lobster again. I was like, I like a
good lobster disk though I love lobster man. But there's
another cool thing from this article. Did you know that
until probably about the twentieth century, people considered lobster like
(23:07):
sea insects. It was for like the the the poor,
and the basically the lower classes. And there were actually
laws apparently in New England about how many times a
week you could feed patients in an insane asylum lobster
because it was considered cruel. I believe that because from
(23:28):
the research I've done, it's amazing that lobsters are considered
some great thing now because they're kind of bottom feeding.
I think they're liking to spiders as close to anything,
and they'll like cannibalize one another. They're just like really crazy, boy,
you dip it in that drawn butter. I know it's tough.
I can kiss lobsters goodbye too. All right, so let's
(23:49):
talk about reproduction. I can handle this first part, but
I did get confused when it comes to the clitellum fertilization.
So so you know, like the band on an earthworm. Well,
let's talk about the first part first. Okay, earthworm reproduction
you wanted. This is the fact for me. They're simultaneous
from aphrodites, all of them. Yeah. I remember that grouper
(24:11):
that was in the tank when we swam with the
whale sharks. Do I that's called a sequential hermaphrodite, where
like at some point during that grouper's life it changes
sex right um, with simultaneous from aphrodites, they have both
reproductive organs of male and female for their whole lives,
which is pretty cool and another great reason why they
have hung around in such vast numbers forever. So what
(24:34):
they do if they want to make love is, uh,
they do a little New Hampshire Vermont action and line
up opposite head to tail. They excrete all that mucus
that we were talking about. They excrete so much of
that that they form a little mucous tube that they
both get in or they're in. I guess that they
(24:57):
used to like rub against one another. Well, the trick
is though there encased in this too bright So when
they release their semen. It's just rubs around until it
finds the semen receptacle right of the other worm. Well obviously, right, yeah,
but yeah, that's exactly right. They rub on one another
with their slime tubes and their semens all over their
slime tubes and then yeah that they that's how they
(25:20):
exchange seminal fluid. So I get all that, but this
next part confuses me a little, and I might suggest
you rewrite it to make it a little easier really
before you publish. Well, I this is this is unedited,
so I need to go through it. But um, okay,
I'll see if I can explain it. And this has
taken um largely from a guy named I think his
(25:40):
name is Jim Conrad. He wrote some pretty good, interesting
and very well written books on earthworms, so it's probably
trying not to paraphrase or plagiarized him, which is why
I'm like, oh, I'll just make it more confusing than he. Um. Basically,
you know the band on the earthworm like saying like Cowler,
that thick the thickest band, that's the cli tellum. Yeah, um,
(26:07):
and uh but in like three or four segments, why
but it's just one segment. So the cli tellum is
responsible for creating another band of mucus as slime tube, right,
and what that does That carries the eggs. It moves
over the earthworm, It moves over the place where the
(26:27):
eggs are stored, attaches the eggs to the slime tube um.
The slime tube then keeps moving forward across the seminal
receptacle where the other worm sperm is now deposited. So
as the slime tube with the eggs attach move over
the seminar receptacle, the eggs become fertilized by the other
(26:50):
worm sperm. That slime tube from the cli tellum keeps
going over the head. And as the worm as it
passes all the way over the worm's head, it closes
off because it's mucus and forms a cocoon. And now
inside that cocoon are fertilized war egs fo to roughly
for like a nightcrawler. It's about four twenty, could be
(27:10):
as little as one twenties the highest I've seen um.
And then there's little baby wear mags in there that
are now fertilized that we'll sit there for like um.
I can't remember how many weeks two to three weeks, okay,
and then you get a little newborn babies and they
can do this every seven to ten days. Yeah, which
is yet another reason why they're abundant and surviving well.
(27:31):
Then the other the other point is both worms that
are in this mating process can become pregnant or can
lay a fertilized cocoon. So there is no such thing
as just a male worm or a female orthorm. They're both.
They're hermaphroditic. That's pretty awesome. Um, really, that's not the
(27:51):
thing come across in this paragraph. Uh, I was slightly confused.
I'll rewrite it then, just slightly. Uh, you have to
do it now. I need to make a note to Okay, Uh,
their life expectancy, it's pretty impressive to a nightcrawler can
live up to twenty years but generally live about six
(28:12):
to nine, which is man, that is a long time
when you're talking about little tiny things that live underfoot. Yeah,
you know, compared to like an insect. I mean, that's
pretty amazing. Red wigglers two to five years, gray worms
between one point to five and two point six years.
Very specific, Well done. That's a mitaki who who came
(28:34):
up with that one. So that's a long time even
for the lowly ugly gray worm. Two and two and
a half years is pretty pretty good. Yeah. And they
actually they have this thing called estivation, which is a
form of hibernation. Yeah. I thought that was really cool too. Um,
it's actually more efficient than hibernation, and hibernation like you
like a bear that's sleeping, they have to gorge themselves
(28:55):
before they hibernate because they're going to be their their
metabolic processes are still operating, so they're still using up
fat stores and food stores. With estivation, it's pretty much
as close to death as you can come, Like almost
all of your body processes just stop, and he's curl
up in a little wormy ball, right, Yeah, to keep
their mucus supply abundant. So that's the only thing they're doing,
(29:18):
is creating mucus moist Yeah. And the reason they're doing
this is because worms definitely have like preferences for like
the temperature um and the conditions on the ground the moisture,
and when things just don't meet their liking, they estivate.
So you can imagine that during the ice age, a
lot of worms estivated and died because it didn't get
(29:41):
any better for ten thou years. Well, when they they're
cold blooded, but when they freeze, they die. Um, you're
talking about their preferences between fifty and humidity, which is
why Georgia has lots of worms. Between fifty nine and
eighty six degree fahrenheit is about what they like. They
can survive, but they're not gonna be as active and
(30:03):
thrive and outside this conditions, right, that's like when their
most active is between those and Um, they will eat
any kind of organic matter. This decaying. But this is
kind of cool. They found out they actually like certain
stuff more than others, which is neto. And the way
I read it was because they like the taste, or
at least that's how I anthropomorpial anthropomorphs species. Uh. In
(30:31):
Washington State they prefer maple over oak, and right here
in Georgia they prefer clover over grass. That's pretty neat.
I got lots of clover in my yard too. They'll
eat the tar out of that stuff, especially if you
tons of worms. If you pulled it and buried it,
it would be gone like that. I wonder how they
do in the clay here. They do very well as
(30:55):
a matter of fact, that they are the reason why,
well there one reason why any water can perk late
through the clay. But man I had clay in my
backyard that like was impenetrable. It seemed like worms can.
Worms can penetrate it really to a certain extent. Yeah. Um,
the one of the so pretty much what Darwin came
(31:17):
up with is that earthworms are extraordinarily helpful. Um, And
we'll talk about in a minute, like scientists have come
to realize like okay, well there's still an invasive species
and as a result, like they it's not all beneficial.
But let's talk about the helpfulness first. One of them
is basically burrowing down through dense clay, dense soils and
(31:39):
creating places called biopores macro pores basically holes in the
ground underneath the ground that let water percolate down to
prevent flooding above ground, which also filters that water it
does as it goes down to the like the water table.
I guess. Yeah, Um, it allows roots to grow more easily,
aration plants aerates. Yeah, it brings oxygen down. It basically
(32:01):
makes soil more usable for the stuff above ground. Well,
they're just basically little tilling machines. They're moving the earth
under there, so you don't have to write. We talked
about nitrogen fixing with their castings, where they take about
casting poop. Is that right, that's that's a nice word
for their poop. Worm castings. Um, And apparently Darwin calculated
(32:27):
it in ten years, ten years worth of worm castings
would cover an acre of of land about two inches thick.
So if you took all the worm castings produced by
a group of worms in an acre in ten years,
you have two inches of worm casting. And they and
like you said earlier, I think they only take about
(32:48):
of the nitrogen for themselves. They're like world, you can
have the other seventy and again it's it's any usable
form now as a nutrient. Pretty awesome, yeah, um, but
it's not all good. No, it's not all good because
they eat too well and they are an invasive species.
(33:08):
So because they consume, uh, what do you have here,
nine thousand, two hundred and forty pounds or of organic
litter for every hectare in eleven weeks. That's too much.
Because spiders and lizards and arthropods and snails and frogs
(33:28):
and slugs and everything else living down there needs that
stuff as well. That's their home, but the worms are
taking it for themselves and they give back they well,
they definitely do like nitrogen, right, but they're taken too much.
So um. There also that there's that litter horizon, that
layer of layer of leaves right above the soil um.
(33:50):
There's this the layer that's closest to the soil surface.
Um that's at the bottom of this leaf layer is
called duff. It's like the sponge, dark organic material that
is actually a nice little place for a seed to
safely just state. So without that duff, without it being
there long enough for a seed to start to germanate
(34:13):
sorry not just eight but german ate um understory plants
like smaller plants, saplings, plants that aren't gonna grow as
big as trees in a woodland um are they have
trouble taking hold. And actually you can see photos side
by side on the Internet of like without worms with worms,
and like the difference is like just this waste land.
(34:35):
Like with worms, it's missing all sorts of little plants
that you see should be there but aren't because the
worms are eating their habitat. Actually, like it can reduce
the understory canopy between like twenty five and the presence
of earthworms can because they eat so much so fast
that not enough leaf litters falling to keep the worms
(34:58):
happy and a seedlings to grow or keep a place
for spiders to live, that kind of thing. Well, and
not just spiders, But that works this way all the
way up to chain, because you're gonna have mammals, larger
mammals that are gonna want to eat vegetables and leaves,
and if they're not there, then they're gonna be in trouble,
and then we're in trouble. Yeah, what about the deer?
(35:19):
Where are we gonna go without deer? I go to
the chicken the section of my grocery store. Everything works out.
You eat chicken instead of deer. I don't need I
don't needt deer. I don't I mean against it. I
just don't come upon it that much. Yeah, you have
to go to like one of those um processing places
out in the country. They always have like deer for sale.
(35:43):
They are also contributing to global warming in a way
because they are admitting a lots of carbon as they
they go through all this organic matter that's gonna some
of some of the carbon is gonna be released there
or some of us going to be released as carbon.
And they have a stat here from Colgate University twenty
(36:03):
what are they New York toothbrushis um They contribute as
much as an additional of carbon released from the soil,
So that's substantial. But there are other studies that show
that actually depending on where you are, Like, uh, that
(36:27):
Colgate was a North American study, they found that like
in Malaysia or Vietnam, like, they're actually better. They actually
locked carbon into the soil. So it really depends on
where they are. But they're not an invasive species in
that study in Vietnam they were native. But at the
end of the day, they do a lot more good
here in North America than bad. Right, probably depending on
(36:49):
whether you're a spider or a small shrub that lives
in the woodland. What if you're human? If you're a human, yeah,
you love the worm. Yeah. I have a couple of
additional little fat X. The biggest worm. I know you've
found some in Japan, but the Australian Jipsland earthworm I
saw twelve feet long, two pounds. Wow, it's a lot
(37:11):
of worm. And what was the japan one? Was that
just another giant earthworm? There's just a bunch of like
I think, because Japan has been a culture for so long,
there's just been a lot of reports on record of
giant earthworms found by farmers, so they had a lot
of stories. It's worth googling giant earthworms because people have
these things wrapped around their neck and stuff, and it's
(37:31):
just this big, mindless worm. Like, No, they're not aggressive
like they're depicted in tremors, but they're still like, uh,
they can eat their weight every day. I saw that.
That's a good one. They are able to move forwards
and backwards, but they like moving forwards. Yeah, okay, and
I didn't know this. If the soil dries up, some
(37:53):
of them can actually lose their cletellum, but once they
get moist again, it can come back. So that's another
survival adaptation. I guess. It's very cool. Pretty cool. So
you got anything else? Do you ever eat them? How
to eat fried worms? I never did. I don't think
if I did, I've blocked it out of my memory
(38:14):
because I don't recall eating. Or if I haven't, it
wasn't they weren't it wouldn't have been fried. It would
have been like somebody who was like, youre eat this right, yeah?
Worm sushi? Yeah, but no I haven't. That was a
great book, though, Did you read that? Sure? Oh? Sure? Classic?
Wasn't it like Judy Bloom? No? It was. I think
it was written by a man and they made a
(38:35):
movie about it. I never saw them. I didn't either.
There's no way I was gonna spoil that childhood memory.
It's a good thing and check. All right, Well, if
you want to learn more about earthworms, probably wait a
couple of weeks and then go see the edited published version,
the better version that includes the fact that they can
move forward and backwards about earthworms. Just type in earth
(39:00):
forms in a couple of weeks at the search bar
at how stuff works dot com. And I said search bar,
which means it's time for listener mail. That's right, Josh.
This is an email before we do the email that
we have a a quick announcement. We get messages from
our fans from time to time around the holidays that
(39:21):
are suffering in some form or another. Because although the
holidays are a great time of the year for for
most folks, sometimes it's a very sad time of year
for others, and uh, we just want to say generally
that we're thinking about you guys. Every time we get
one of these emails, we reply and it's it's you know,
it's very sad and we wish it was more we
could do. But we were thinking about either in the holidays,
(39:44):
and we hope everyone out there and this stuff you
should know Army is uh is hanging in there. Check.
That was very nice of you know. So onto the email,
I'm gonna call this sharpa overdue sharp at email from
graces Hey, guys and Jerry using it as a collective,
she points out. I know this is a while back,
but I actually met a sherpa. He's a kid who
(40:05):
went to my school for a little while, and he
was totally cool with me asking him a thousand and
one questions. He thought it was cool that I knew
some information, and when I told him about your podcast episode,
he wanted to listen to some of it. But before
I give you his feedback, here's his story. Until he
was five, he lived in a village near Mount Everest,
but not so close that he ever got a good
(40:25):
look at it. I couldn't imagine he was that near,
And then I would think you have to be really
really near it to not get a good look at Oh,
maybe that was the case. He was so close it
was just like a wall, a wall of rock. Uh.
And she says, even if he did get a good
look at it, he was only five, so he may
not remember it. He had to leave his village though,
(40:47):
because they were threatened by the maoists, so he moved
to a city as a refugee. Uh. And he lived
there until last year. From what I understand, they were
still under the threat from malice, so they came to
America as a refugee. Ill Um. Here's his little additional
effects as the plural of Sherpa is Sherpa's So we
were right cool. You pronounced the region Solu Kumbo correctly,
(41:11):
and he was very excited about that. And he said,
there are a lot of potatoes. Now, remember we they
started growing potatoes at a certain point and that's the
bumper crop. I guess. So that's all he heard of
the podcast, only about five minutes of it. He didn't uh.
Grace didn't want to make him listen to the whole
thing because she felt like he already knew most of
(41:32):
the stuff and she didn't want him for him, so uh,
he was excited about it. She was excited about it,
and she just wants to say thanks for reading this
on the year, and that is from Grace. Thanks a lot, Greig.
Thank you to your Sherpa friend too for supporting us.
And welcome to America, Sherpa boy, and good luck here.
(41:53):
Um wow, Chuck here just spreading glad tidings all over
the place. Aren't you a great joy? Um? If you
wanna spread glad tidings to us or to anybody else
through us, you can send us an email at stuff
podcast at how stuff works dot com. For moral this
(42:15):
and thousands of other topics. Is it how stuff works
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thousand twelve camera. It's ready. Are you
Brought to you by the reinvented two thousand twelve camera.
It's ready. Are you welcome to Stuff you should know
from House Stuff Works dot Com. Hey, and welcome to
the podcast. I'm Josh Clark. There's Charles W Chuck Bryant
and that makes his debut take two. Rarely do we
(00:25):
have a take two, very rarely, but we did today.
Yeah we did. We started just kind of talking and
shop and Jerry's like, what are you guys doing? Yea, um,
but anyway, here we are. We're back, We're happy, everything's
good and um we're we're gonna talk a little bit
about earthworms, right, Yes? Are you feeling good about this one?
(00:47):
I am very interesting stuff. I wrote this article specifically
so we can podcast on it. So, chuck y, have
you heard of a man named Charles Darwin? You know
I love Chuckie d So chuck Chuck the Charles Darwin
um very famous for the On the Origin of the
Species um incredibly important work. Did you know though, that
(01:12):
The Origin of the Species was out sold in the
nineteenth century by another book of his called The Formation
of Vegetable Mold through the Action of Worms, with observations
on their habits that sold more copies for real. Yeah,
through throughout the rest of the nineteenth century. It was
published in one UM and I think like the Origin
(01:33):
of the species came a little after that. So, but
just during the nineteenth century for a while there, um,
the formation of vegetable mold was crazy out selling on
the origin of the species. I saw today where he
studied earthworms for thirty nine years. Yeah, it was. This
book was very near and dear to his heart, like
(01:54):
this topic was. He spent a lot of time really
looking at earthworm. I guess he died because why would
you give up at thirty nine? I would say, let's
just make it an even forty. I think he wrote
the book and was like, Okay, don't you go. I'm done.
I'm onto some Let's go to Galapagos exactly you know,
um he uh. He came up with in this thirty
(02:16):
nine years and in this book some very um, very
well understood observations that are still accepted today. Right. Um.
As a matter of fact, we have a quote from
him as read by him. All right, you want to hear.
It may be doubted whether there are many other animals
which have played so important apart in the history of
(02:36):
the world, as have these lowly organized creatures. So there
you have it. Wow, the earthworm is very, very important.
I didn't know he talked like that. I didn't either.
It's kind of surprising, um, but he. Uh. This this idea,
this concept that the earthworm is extremely important to the
(02:57):
earth was kind of put forth by Darwins and accepted
as gospel since them and in the decades and centuries
since Darwin. He did such a good job that earthworm
research kind of fell by the wayside. Scientific community was classifying,
classifying as extinct, like worms they just hadn't seen in
a while that would just later pop back up, like
(03:19):
the giant pelouse earthworm in the Pacific northwest of the
United States. It was thought to be extinct, classified as
such in the eighties, and then in two thousen it
pops up and they're like, oh, it's not extinct. The
worm popped up. And that happens a lot with earthworms,
like people just classified him as extinct. So this kind
(03:40):
of like these appearances of kind of reinvigorated science and
it's inquiry into earthworms. I wonder how he got on it, Darwin. Yeah,
I mean out of all the different things he was studying.
I wonder how he honed in on the earthworm and
knew its value, just because if no one else had
studied its value, I would never look at an earthworm
and think it's very valid able at all. No, but
(04:01):
people before Darwin realized the value of earthworms like aristotles
of the soil. No, but he's the one who dedicated
thirty nine years to studying them. Um So just in
sheer size alone, um, I guess in sheer volume is
a better way to put it. Earthworms are there. They
(04:22):
have a substantial impact on earth. I think, so three
thousand species. Notice it didn't say species species. You know
people say species. Sorry species Germans know a lot of
people say species as species, species, species, species. I don't
(04:43):
know which one I say. I think both acceptable. I
think not species. Yeah. Uh. They have reigned in size
from about a centimeter to nine feet, although they go
away more than that. Yeah. I think the world record
I found was one in South Africa was twenty two
ft long. Twenty two ft long earthworm. That's huge, and
(05:03):
there are plenty others. Japan has some giant ones, Australia
does too. Of course, I found one. We'll talk about that.
Lots of giant freaks of nature. But here's here's the
cool stat of the day for me. Uh Plus, we
get to say the word hectare just close to two
and a half acres. Yeah, it's like two point four
seven single hecked air. You can find five hundred thousand
(05:23):
to two million worms, and their total biomass wet biomass
equals ten times a total weight of all the other
animals living above ground combined on that same size spot
of land, on that same heck there. Yeah, that's nutty.
That is nutty, especially considering that worms don't go that
deep into the soil. Let's say there's twelve deer on
(05:46):
that heck dare I mean, that's gonna be a lot
of weight right there. It's just from the deer. Say
say each deer weighs a hundred and fifty pounds, it's
like eight hundred pounds and a dozen deer some amount
of kilograms. Yeah, that's probably like n So the point
is a lot of worms. Yeah, there are, there's a
(06:06):
ton of worms. Um, they're spread all over the place.
But here's an interesting fact. If um, if you've read fourteen,
you probably already know this Charles Man's brilliant follow up
to his triumphant I can't wait for fo Yeah, look
out for that one. He's just gonna pick some random
(06:26):
date like um. If the if you go into uh,
the average North American woods in the northern United States,
say um, and you find an earthworm, that earthworm. Had
you dug in the same spot five hundred years before,
you wouldn't have found any earthworms there. Like all earthworms
(06:48):
in North America and Canada above about the forty degree
latitude UM are new. They're relatively recent immigrants from Asia
and Europe, and they hitched a ride thanks to the
coling to America in plants the soil. Yeah, root balls
that were attached to plants um that were imported to
the United States and Canada. UM from Asia and Europe. Yes, Chuck,
(07:13):
I have a question. Yes, I have a few questions
for you, because you wrote this and it's always nice
to speak to the author, and you're right in front
of me. So how's how's that I'm right here? Uh?
Do they know what was here before the ice age
that killed off all the original native species? Surely there
were worms. Then it's an excellent question. No, they don't know.
(07:34):
Now they know that, I guess not because it was
pretty ice age. It's not like they had records. There
were some there's there's fossil there's fossil records of earthworms
that go back like a hundred and sixty five million years,
like there was a huge giant earthworm that it was
armor plated. Right. But yeah, but the stuff in North America,
apparently the fossil record is fairly incomplete here. Um, they
(07:55):
do suspect that a lot of worms made their way
southward towards warmer ground when these glacial ice sheets started
bearing down from Canada. Everything, a lot of stuff died,
some stuff high tail it south. So you can bet
that if you go to southern California or Mexico and
big and find a worm, that's probably the same species
(08:17):
that were higher up, species that were further north, you know,
prior to the last because you make a point later
that it's considered an invasive species because it's not native.
But I thought, well, surely they weren't that different before
the ice age, right. Well, the species the species that
are here, especially um, the common European earthworm, which we
(08:39):
here in the United States called nightcrawlers. That's from Europe,
which is why it's the common European nightworm. Those are
recent immigrants. Those guys weren't here before, right. So the
other reason they're invasive, Chuck, is since the end of
the last ice Age, say ten to twenty thousand years ago,
these woodlands in the north in the United States, uh developed,
(09:02):
they adapted, they changed to life without earthworms. Now they're
having to adapt to life with earthworms. That makes sense,
which makes earthworms invasive. Now, yeah, I get that, that
makes perfect sense. All right. Well, hey, look at there.
We covered a bit at the end. Yeah, we're gonna
get out here early now thanks. Another cool point you
make is if you dig down into the earth in
(09:25):
your backyard, in the earth a couple of feet, you're
probably gonna find all three classifications of earthworm because they're
they're classified by where they live in the soil. Because
they're also similar in appearance. I mean, yeah, except for
like maybe how thick around they are, how many segments
they have, um, how long they are. That's pretty much
(09:45):
the differences in earthworms. They're all very similar like wherever
you are. But there are three classes. And like you said,
they're based on where they live, Like there's the ones
above ground. Yeah, I've been pronouncing in my head eyak,
but GX sounds a lot I like gay do you like? Guy?
Let's go with that. Well, because it's a it's derivative
(10:06):
of gaya earth and eppie is above. So this is this,
This is the classification of earthworms that live like in
the leaf litter, which is also called the litter horizon,
that pile of leaves and organic material that that covers
the soil that these red wigglers. Red worms have a
lot to do with the fact that it's you know,
(10:28):
eventually gonna be black and slimy. Yeah, almost all of
the fact all they have almost everything to do with that.
I mean there's other like microbes and protozoa and other
stuff like that breaking it down, but the worms are
the ones that can get it done. So those red
wigglers are fun to play with if you're a kid.
Uh so are the next level down you get to
the indo gaeic as we'll say. Now they live in
(10:49):
the top soil that sort of you know how deep
like the first several inches, Yeah, you know, like the
dark top soil. Good stuff. As I like to call it. Yeah,
and they spend their whole lit beneath the soil, which
is why they're usually like very light in color, gray pinkish,
they're white, kind of uglier. Yeah. Have you ever seen
that movie The Layer of the White Worm. That's a
(11:12):
great horror. Yeah, I've heard of Hugh Grants first movies.
Awesome was he the white Worm? No? He was the dude. Okay,
he played a man. Uh. You say because they live
under the soil full time, that the least amount of
information is known about them. But another question the next
(11:33):
level down that uh and and essek they hold the
nightcrawlers the deepest dwelling ones. But it seems like we
know more about them than the other guys, a little
pink and gray guys. So why would that be? Well,
the reason is is because the little pink and gray guys,
the epigaic ones um, spend their whole lives underground, so
(11:55):
they just stay there. Yes, okay, they also make horizontal burrows, right,
so like they don't have to come up at all.
They don't. They have almost nothing to do with leaf decomposition.
So the nightcrawlers come up and then go back down
exactly Not only do nightcrawlers come up, they come up
and travel as far as like sixty two ft in
a night looking for food. Like they hang out above ground.
(12:17):
The epigaic ones you have to dig down for them.
They're not coming up to greet you. So the scientists
don't have spades. That's what I'm saying, man Like the
like science generally was like, Okay, Darwin wrote the book
on earthworms. You don't have to any more investigation about that. Interesting.
Another cool fact about the nightcrawler is that they go
upstairs to to grab some food and bring it back down.
(12:41):
They're like, hey, that leaf is really choice and moist,
so I'm gonna grab it and take it back downstairs
and just chow. So my little belly bursts. I love that. Yeah,
but it also kind of gives you an idea of
like just how powerful like a nightcrawler is it drags
its food back to its house. You know. I used
to hate fishing with worms. That's that and the potential.
(13:07):
One time I went fishing and caught brim, and um,
I didn't have a hook remover and this thing, this
brim swallowed this hook like crazy, and I was trying
so hard to get it out, and it was just
like obvious that this weren't This fish was dying. And
one of his buddies was just sitting there almost at
the bank, almost up on the ground, watching me, just
(13:29):
looking at me like why did you do that? So
that and then the that she club that one, I
was like stopped looking at me. Fishing just punched the water.
Um that the potential of a fish dying, and then
the guarantee of worms dying, uh made me quit fishing
forever sticks because fish is fun. Fishing is fun. I
(13:50):
love to fish, yeah, but I just don't do it anymore.
All right, Well that's sad for you. Oh club fish
like clubbing, but I won't actually use like a roden reel.
Earthworms are segmented Josh, which is also very interesting. Uh.
They are from the phylum Annelid, which means ringed worm.
(14:12):
And there's about a hundred to a hundred and fifty
of these rings and they're each controlled separately little muscles,
which is very important because they expand and contract to
move their little slimy bodies forward. And they have these
bristles at the front towards the head the anterior and
um that are retractable. They're called settee, and um, they
can just go big and dig into the dirt and
(14:36):
hold the head in place while the rest of the
body kind of contracts to get smaller to move forward
like that. So these sete you go in and out
depending on whether the heads moving or is it needs
to be anchored so the rest of the body can
catch up. And that's how they scoot along at sixty
two per night for nightcrawlers. So um, pretty much, Chuck,
(15:00):
I don't know what we're naming this one yet, but
one of the one of them the suggestions you made
was earthworms eating and pooping machines kind of like sharks,
and I mean kind of um, but possibly even more
beneficial than sharks. Sharks are like an apex predator. Right
of course, earthworms are not an apex predator, but like
(15:21):
I said, Aristotle call him the intestine of the soil.
And one of the reasons why is because they just
eat and eat and eat, and the stuff that they
do eat they poop out. And it's actually what's crazy,
remember the digestion um episode, So like the stuff that
comes out of us, it's like nobody needs that. It's
(15:42):
total waste with the worm, it's actually better than it
was before. Warm poop is better than the food it eats. Yeah,
that's pretty cool. That is pretty cool. And the way
it eats is even cooler. I think. Um, they obviously
eat and you're not gonna be able to tell a
huge difference between the mouth end and the anus end
(16:04):
unless you really dig your fingers in there. But at
the mouth end, they're gonna they're gonna pass dirt and
organic matter into their mouth and it's gonna go into
an area called the crop where they store it for
a little while, then into the gizzard. And this is
the coolest part to me. In the gizzard, they have
these tiny pebbles that they've already eaten, and those pebbles
(16:25):
grind the food up even more like a little food
processor to make it easier to pass through. That is
so cool. And uh, in the intestinal walls, they they're
aligned with blood vessels and sort of like our own
blood vessels, they absorb and distribute nutrients. So it's not
that much different than people. Yeah, no, it's not the
thing about earthworms though, is the nutrients, especially nitrogen um,
(16:51):
that they eat that they pass out is about of
what was say, locked into a leaf, so they only
keep like a order of the available nitrogen for themselves.
But through digestion, what was once just locked into this
leaf and was totally unusable to like a tree root,
is now digested and broken up and available. It's called
(17:15):
nitrogen fixing. And that's what worms do. They're casting their
feces is broken down nitrogen, which is why people use
worms for composting. That's exactly right there, the secret ingredient.
While they're not secret but key ingredient to compost. But
that's the that's the epigayic right. The ones that live
(17:37):
above ground, the compost ones, the earthworms, like the annesic ones,
they're big into composting two but they do it below ground.
Um earthworm has five hearts. Kind of a neat fact
right there. I would say aortic arches and uh I
saw I think I saw in another photo like they
(17:57):
have one of the main ones is that and then
four other ones? Are they all equal? I think that
they are. There's a main one, I believe, so you
think I know you and chuck. The breathing through their
skin is another cool trait. They don't have lungs, but
they still need to breathe, so they just pass it
passively through the skin inhaling and exhaling. There's no inhaler
(18:22):
exhale because it just happens. But I call that an inhale.
Even though when I was writing this, I had to
go back. I was like, no, they're not inhaler. Yeah. Um,
as long as their skin is coated in this mucus
that they produced, that's how air exchanges is allowed to
take place. Um. And if there's enough broken down available
(18:43):
oxygen in a body of water, a worm can live
in water. It can survive in water for a while
because the air exchange is still taking place. They're just
grabing oxygen. Yeah. Um. The problem is is when they
encounter like really dry hot air like above ground. Yeah.
I think we've all seen that sad, sad site. Right.
So if you if you've ever seen like a worm
(19:05):
that's curled up and is dry on the sidewalk that
were suffocated to death because it wasn't able to breathe.
That's mucus dried out. I couldn't breathe, you know, and
all it needed to do is reach those leaves, but
it failed on the sidewalk and that happens a lot
in Georgia. Obviously you see a lot of those in
the summertime. Uh. And to to make sure that they survive.
(19:28):
They don't have eyes, so it's not like they can say, oh,
the sun's out, but they're able to sense light through
these photo sensitive cells on their skin that convert light
into electrical impulses. So they feel this and say, hey,
it's sunny out, I need to burrow down a little
bit more. Yeah, pretty cool, yep. And this is why
these buggers have survived for so long. It is. And um,
(19:50):
that's also the role for their brain that their brain
plays is to say, I'm sensing some light, so let's
move down a little for there where there's not light.
That's pretty much the extent of the worm brain. Yeah,
that's what I saw. They said, if you remove the brain,
then you're hardly going to notice any change in behavior,
(20:11):
except I guess they would dry up in the sun. Yeah. Right,
So maybe that's what we've seen is brainless worms on sidewalks. Yeah,
or maybe they lost part of it. Someone remove their brains.
We can go ahead and talk about that the regeneration. Okay,
go ahead, because I need some explanation on that part.
I get it a worm if if it's part of
(20:32):
it is chopped off somehow, Um, they can regenerate uh
more more towards the tail than the head. Is that right?
So like that if you cut a worm in half,
only one half is going to regenerate. Most likely it's
the head end that they have an easier time regenerating
their tail than they have their head. That makes sense. Um.
(20:53):
The thing is is one of the joys of this
is like anytime there's a question or something's vague, can
be like, yeah, science really dropped the ball on earthworm
research for a century. They there there's evidence that like
and both sides can regenerate into two new worms. People
have documented this supposedly, Um, there's like different, um, contrary
(21:17):
evidence about how much could regenerate or how little, like
how little of a segment you need to regenerate into
a new worm. So there's a bunch of apparently there's
a bunch of evidence out there that says like worms
are spectacular regenerating and others are saying they're a little
more limited than we think. Well, any kind of regeneration
is pretty amazing if you ask me, Yeah, I agree.
(21:37):
But if you want to make a bet with your friend,
a very cruel friend who had just cut a worm
directly in half, which end was going to regenerate, always
put your money on the tail end. I could never
I mean, it's just a little worm. I could never
do that because they just squirmed so much like they're
in horrible pain. You know. Yeah, have you read considered
the lobster David Foster Wallace, like his his article for
(22:01):
Gourmet magazine. Well, they sent him to like the Lobster Festival,
and we were just expecting like a kind of a
travel foodie article, and instead he went and did a
bunch of research on whether or not lobsters feel pain
because they're boiled to death. Yea, and definitely make noises
to when that happened. They do. They scratch like the
pot trying to get out. They do. But the key
(22:24):
is is like, yes, surely they feel pain. Of course
they feel pain. Um, they it's been shown that they
have nerve receptors that you know, since pain, do they
experience suffering? So that weren't squirming in in pain and
suffering or just pain and really doesn't matter, I mean,
and think inflicting pain on anything is cruel, but inflicting
(22:44):
suffering is evil. Yeah. Yeah, I don't need a much lobster.
Yeah you me um read that and was like, I'm
never eating lobster again. I was like, I like a
good lobster disk though I love lobster man. But there's
another cool thing from this article. Did you know that
until probably about the twentieth century, people considered lobster like
(23:07):
sea insects. It was for like the the the poor,
and the basically the lower classes. And there were actually
laws apparently in New England about how many times a
week you could feed patients in an insane asylum lobster
because it was considered cruel. I believe that because from
(23:28):
the research I've done, it's amazing that lobsters are considered
some great thing now because they're kind of bottom feeding.
I think they're liking to spiders as close to anything,
and they'll like cannibalize one another. They're just like really crazy, boy,
you dip it in that drawn butter. I know it's tough.
I can kiss lobsters goodbye too. All right, so let's
(23:49):
talk about reproduction. I can handle this first part, but
I did get confused when it comes to the clitellum fertilization.
So so you know, like the band on an earthworm. Well,
let's talk about the first part first. Okay, earthworm reproduction
you wanted. This is the fact for me. They're simultaneous
from aphrodites, all of them. Yeah. I remember that grouper
(24:11):
that was in the tank when we swam with the
whale sharks. Do I that's called a sequential hermaphrodite, where
like at some point during that grouper's life it changes
sex right um, with simultaneous from aphrodites, they have both
reproductive organs of male and female for their whole lives,
which is pretty cool and another great reason why they
have hung around in such vast numbers forever. So what
(24:34):
they do if they want to make love is, uh,
they do a little New Hampshire Vermont action and line
up opposite head to tail. They excrete all that mucus
that we were talking about. They excrete so much of
that that they form a little mucous tube that they
both get in or they're in. I guess that they
(24:57):
used to like rub against one another. Well, the trick
is though there encased in this too bright So when
they release their semen. It's just rubs around until it
finds the semen receptacle right of the other worm. Well obviously, right, yeah,
but yeah, that's exactly right. They rub on one another
with their slime tubes and their semens all over their
slime tubes and then yeah that they that's how they
(25:20):
exchange seminal fluid. So I get all that, but this
next part confuses me a little, and I might suggest
you rewrite it to make it a little easier really
before you publish. Well, I this is this is unedited,
so I need to go through it. But um, okay,
I'll see if I can explain it. And this has
taken um largely from a guy named I think his
(25:40):
name is Jim Conrad. He wrote some pretty good, interesting
and very well written books on earthworms, so it's probably
trying not to paraphrase or plagiarized him, which is why
I'm like, oh, I'll just make it more confusing than he. Um. Basically,
you know the band on the earthworm like saying like Cowler,
that thick the thickest band, that's the cli tellum. Yeah, um,
(26:07):
and uh but in like three or four segments, why
but it's just one segment. So the cli tellum is
responsible for creating another band of mucus as slime tube, right,
and what that does That carries the eggs. It moves
over the earthworm, It moves over the place where the
(26:27):
eggs are stored, attaches the eggs to the slime tube um.
The slime tube then keeps moving forward across the seminal
receptacle where the other worm sperm is now deposited. So
as the slime tube with the eggs attach move over
the seminar receptacle, the eggs become fertilized by the other
(26:50):
worm sperm. That slime tube from the cli tellum keeps
going over the head. And as the worm as it
passes all the way over the worm's head, it closes
off because it's mucus and forms a cocoon. And now
inside that cocoon are fertilized war egs fo to roughly
for like a nightcrawler. It's about four twenty, could be
(27:10):
as little as one twenties the highest I've seen um.
And then there's little baby wear mags in there that
are now fertilized that we'll sit there for like um.
I can't remember how many weeks two to three weeks, okay,
and then you get a little newborn babies and they
can do this every seven to ten days. Yeah, which
is yet another reason why they're abundant and surviving well.
(27:31):
Then the other the other point is both worms that
are in this mating process can become pregnant or can
lay a fertilized cocoon. So there is no such thing
as just a male worm or a female orthorm. They're both.
They're hermaphroditic. That's pretty awesome. Um, really, that's not the
(27:51):
thing come across in this paragraph. Uh, I was slightly confused.
I'll rewrite it then, just slightly. Uh, you have to
do it now. I need to make a note to Okay, Uh,
their life expectancy, it's pretty impressive to a nightcrawler can
live up to twenty years but generally live about six
(28:12):
to nine, which is man, that is a long time
when you're talking about little tiny things that live underfoot. Yeah,
you know, compared to like an insect. I mean, that's
pretty amazing. Red wigglers two to five years, gray worms
between one point to five and two point six years.
Very specific, Well done. That's a mitaki who who came
(28:34):
up with that one. So that's a long time even
for the lowly ugly gray worm. Two and two and
a half years is pretty pretty good. Yeah. And they
actually they have this thing called estivation, which is a
form of hibernation. Yeah. I thought that was really cool too. Um,
it's actually more efficient than hibernation, and hibernation like you
like a bear that's sleeping, they have to gorge themselves
(28:55):
before they hibernate because they're going to be their their
metabolic processes are still operating, so they're still using up
fat stores and food stores. With estivation, it's pretty much
as close to death as you can come, Like almost
all of your body processes just stop, and he's curl
up in a little wormy ball, right, Yeah, to keep
their mucus supply abundant. So that's the only thing they're doing,
(29:18):
is creating mucus moist Yeah. And the reason they're doing
this is because worms definitely have like preferences for like
the temperature um and the conditions on the ground the moisture,
and when things just don't meet their liking, they estivate.
So you can imagine that during the ice age, a
lot of worms estivated and died because it didn't get
(29:41):
any better for ten thou years. Well, when they they're
cold blooded, but when they freeze, they die. Um, you're
talking about their preferences between fifty and humidity, which is
why Georgia has lots of worms. Between fifty nine and
eighty six degree fahrenheit is about what they like. They
can survive, but they're not gonna be as active and
(30:03):
thrive and outside this conditions, right, that's like when their
most active is between those and Um, they will eat
any kind of organic matter. This decaying. But this is
kind of cool. They found out they actually like certain
stuff more than others, which is neto. And the way
I read it was because they like the taste, or
at least that's how I anthropomorpial anthropomorphs species. Uh. In
(30:31):
Washington State they prefer maple over oak, and right here
in Georgia they prefer clover over grass. That's pretty neat.
I got lots of clover in my yard too. They'll
eat the tar out of that stuff, especially if you
tons of worms. If you pulled it and buried it,
it would be gone like that. I wonder how they
do in the clay here. They do very well as
(30:55):
a matter of fact, that they are the reason why,
well there one reason why any water can perk late
through the clay. But man I had clay in my
backyard that like was impenetrable. It seemed like worms can.
Worms can penetrate it really to a certain extent. Yeah. Um,
the one of the so pretty much what Darwin came
(31:17):
up with is that earthworms are extraordinarily helpful. Um, And
we'll talk about in a minute, like scientists have come
to realize like okay, well there's still an invasive species
and as a result, like they it's not all beneficial.
But let's talk about the helpfulness first. One of them
is basically burrowing down through dense clay, dense soils and
(31:39):
creating places called biopores macro pores basically holes in the
ground underneath the ground that let water percolate down to
prevent flooding above ground, which also filters that water it
does as it goes down to the like the water table.
I guess. Yeah, Um, it allows roots to grow more easily,
aration plants aerates. Yeah, it brings oxygen down. It basically
(32:01):
makes soil more usable for the stuff above ground. Well,
they're just basically little tilling machines. They're moving the earth
under there, so you don't have to write. We talked
about nitrogen fixing with their castings, where they take about
casting poop. Is that right, that's that's a nice word
for their poop. Worm castings. Um, And apparently Darwin calculated
(32:27):
it in ten years, ten years worth of worm castings
would cover an acre of of land about two inches thick.
So if you took all the worm castings produced by
a group of worms in an acre in ten years,
you have two inches of worm casting. And they and
like you said earlier, I think they only take about
(32:48):
of the nitrogen for themselves. They're like world, you can
have the other seventy and again it's it's any usable
form now as a nutrient. Pretty awesome, yeah, um, but
it's not all good. No, it's not all good because
they eat too well and they are an invasive species.
(33:08):
So because they consume, uh, what do you have here,
nine thousand, two hundred and forty pounds or of organic
litter for every hectare in eleven weeks. That's too much.
Because spiders and lizards and arthropods and snails and frogs
(33:28):
and slugs and everything else living down there needs that
stuff as well. That's their home, but the worms are
taking it for themselves and they give back they well,
they definitely do like nitrogen, right, but they're taken too much.
So um. There also that there's that litter horizon, that
layer of layer of leaves right above the soil um.
(33:50):
There's this the layer that's closest to the soil surface.
Um that's at the bottom of this leaf layer is
called duff. It's like the sponge, dark organic material that
is actually a nice little place for a seed to
safely just state. So without that duff, without it being
there long enough for a seed to start to germanate
(34:13):
sorry not just eight but german ate um understory plants
like smaller plants, saplings, plants that aren't gonna grow as
big as trees in a woodland um are they have
trouble taking hold. And actually you can see photos side
by side on the Internet of like without worms with worms,
and like the difference is like just this waste land.
(34:35):
Like with worms, it's missing all sorts of little plants
that you see should be there but aren't because the
worms are eating their habitat. Actually, like it can reduce
the understory canopy between like twenty five and the presence
of earthworms can because they eat so much so fast
that not enough leaf litters falling to keep the worms
(34:58):
happy and a seedlings to grow or keep a place
for spiders to live, that kind of thing. Well, and
not just spiders, But that works this way all the
way up to chain, because you're gonna have mammals, larger
mammals that are gonna want to eat vegetables and leaves,
and if they're not there, then they're gonna be in trouble,
and then we're in trouble. Yeah, what about the deer?
(35:19):
Where are we gonna go without deer? I go to
the chicken the section of my grocery store. Everything works out.
You eat chicken instead of deer. I don't need I
don't needt deer. I don't I mean against it. I
just don't come upon it that much. Yeah, you have
to go to like one of those um processing places
out in the country. They always have like deer for sale.
(35:43):
They are also contributing to global warming in a way
because they are admitting a lots of carbon as they
they go through all this organic matter that's gonna some
of some of the carbon is gonna be released there
or some of us going to be released as carbon.
And they have a stat here from Colgate University twenty
(36:03):
what are they New York toothbrushis um They contribute as
much as an additional of carbon released from the soil,
So that's substantial. But there are other studies that show
that actually depending on where you are, Like, uh, that
(36:27):
Colgate was a North American study, they found that like
in Malaysia or Vietnam, like, they're actually better. They actually
locked carbon into the soil. So it really depends on
where they are. But they're not an invasive species in
that study in Vietnam they were native. But at the
end of the day, they do a lot more good
here in North America than bad. Right, probably depending on
(36:49):
whether you're a spider or a small shrub that lives
in the woodland. What if you're human? If you're a human, yeah,
you love the worm. Yeah. I have a couple of
additional little fat X. The biggest worm. I know you've
found some in Japan, but the Australian Jipsland earthworm I
saw twelve feet long, two pounds. Wow, it's a lot
(37:11):
of worm. And what was the japan one? Was that
just another giant earthworm? There's just a bunch of like
I think, because Japan has been a culture for so long,
there's just been a lot of reports on record of
giant earthworms found by farmers, so they had a lot
of stories. It's worth googling giant earthworms because people have
these things wrapped around their neck and stuff, and it's
(37:31):
just this big, mindless worm. Like, No, they're not aggressive
like they're depicted in tremors, but they're still like, uh,
they can eat their weight every day. I saw that.
That's a good one. They are able to move forwards
and backwards, but they like moving forwards. Yeah, okay, and
I didn't know this. If the soil dries up, some
(37:53):
of them can actually lose their cletellum, but once they
get moist again, it can come back. So that's another
survival adaptation. I guess. It's very cool. Pretty cool. So
you got anything else? Do you ever eat them? How
to eat fried worms? I never did. I don't think
if I did, I've blocked it out of my memory
(38:14):
because I don't recall eating. Or if I haven't, it
wasn't they weren't it wouldn't have been fried. It would
have been like somebody who was like, youre eat this right, yeah?
Worm sushi? Yeah, but no I haven't. That was a
great book, though, Did you read that? Sure? Oh? Sure? Classic?
Wasn't it like Judy Bloom? No? It was. I think
it was written by a man and they made a
(38:35):
movie about it. I never saw them. I didn't either.
There's no way I was gonna spoil that childhood memory.
It's a good thing and check. All right, Well, if
you want to learn more about earthworms, probably wait a
couple of weeks and then go see the edited published version,
the better version that includes the fact that they can
move forward and backwards about earthworms. Just type in earth
(39:00):
forms in a couple of weeks at the search bar
at how stuff works dot com. And I said search bar,
which means it's time for listener mail. That's right, Josh.
This is an email before we do the email that
we have a a quick announcement. We get messages from
our fans from time to time around the holidays that
(39:21):
are suffering in some form or another. Because although the
holidays are a great time of the year for for
most folks, sometimes it's a very sad time of year
for others, and uh, we just want to say generally
that we're thinking about you guys. Every time we get
one of these emails, we reply and it's it's you know,
it's very sad and we wish it was more we
could do. But we were thinking about either in the holidays,
(39:44):
and we hope everyone out there and this stuff you
should know Army is uh is hanging in there. Check.
That was very nice of you know. So onto the email,
I'm gonna call this sharpa overdue sharp at email from
graces Hey, guys and Jerry using it as a collective,
she points out. I know this is a while back,
but I actually met a sherpa. He's a kid who
(40:05):
went to my school for a little while, and he
was totally cool with me asking him a thousand and
one questions. He thought it was cool that I knew
some information, and when I told him about your podcast episode,
he wanted to listen to some of it. But before
I give you his feedback, here's his story. Until he
was five, he lived in a village near Mount Everest,
but not so close that he ever got a good
(40:25):
look at it. I couldn't imagine he was that near,
And then I would think you have to be really
really near it to not get a good look at Oh,
maybe that was the case. He was so close it
was just like a wall, a wall of rock. Uh.
And she says, even if he did get a good
look at it, he was only five, so he may
not remember it. He had to leave his village though,
(40:47):
because they were threatened by the maoists, so he moved
to a city as a refugee. Uh. And he lived
there until last year. From what I understand, they were
still under the threat from malice, so they came to
America as a refugee. Ill Um. Here's his little additional
effects as the plural of Sherpa is Sherpa's So we
were right cool. You pronounced the region Solu Kumbo correctly,
(41:11):
and he was very excited about that. And he said,
there are a lot of potatoes. Now, remember we they
started growing potatoes at a certain point and that's the
bumper crop. I guess. So that's all he heard of
the podcast, only about five minutes of it. He didn't uh.
Grace didn't want to make him listen to the whole
thing because she felt like he already knew most of
(41:32):
the stuff and she didn't want him for him, so uh,
he was excited about it. She was excited about it,
and she just wants to say thanks for reading this
on the year, and that is from Grace. Thanks a lot, Greig.
Thank you to your Sherpa friend too for supporting us.
And welcome to America, Sherpa boy, and good luck here.
(41:53):
Um wow, Chuck here just spreading glad tidings all over
the place. Aren't you a great joy? Um? If you
wanna spread glad tidings to us or to anybody else
through us, you can send us an email at stuff
podcast at how stuff works dot com. For moral this
(42:15):
and thousands of other topics. Is it how stuff works
dot com. To learn more about the podcast, click on
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