[♩INTRO] Not all animals fart. Birds, for example, don’t have the pleasure. They have reputations to protect, for one
thing. Also, they lack the gut bacteria that produce
intestinal waste gas. But that doesn’t mean that we humans are
alone in farting. There are animals that pass gas. If you have a dog, you probably know this. And it’s not just something they do after
a bowl of broccoli slaw, either. For some animals, farting is a matter of life
and death. So here are six animals that use various types
of gas, whether excreted from the rear or someplace near there, to some
pretty creative ends. First, for the Sonoran coral snake, farting
can actually be the key to getting out of trouble. Sonoran coral snakes fart to ward off threats. Because venom alone wasn’t enough of a defensive
strategy, apparently. So these snakes have a couple of aposematic,
or warning, signals they use to tell other animals to back off. They have brightly-colored bands of red, black,
and yellow or white. They also fart. Or more specifically, they force air out of
their cloaca, an opening used for both waste and reproduction -- which makes
a popping sound. Researchers say the “cloacal popping”
does actually sound like a human fart. So I don’t know why we aren’t calling
our own farts “anal popping”. If we’re going to call that “cloacal popping” Science. [laughs] Though it hasn’t been studied extensively,
which is a shame honestly, the sound seems to be tailored to scare off anything
that grabs or touches the snake. Or at least make it like, stand back for a
second and say, “Dude, did you seriously just fart right
in my face?” Next, remember that kid in summer camp who could swallow air and burp his ABCs? Well, herring do that. Kinda. They take air into their swim bladders, but
then it comes out the other end. When they release the gas, it makes a rapid-fire
sound that you probably wouldn’t recognize as
flatulence. In a 2003 study, researchers dubbed this sound Fast Repetitive Ticks, or FRTs for short. Because no, you are not required to hand in
your sense of humor once you become a scientist. You do get to name fish farts “FRTs”. The researchers mostly observed these sounds
at night, so they suggested it might help the fish find
each other in the dark. You see, herring are social, and they like
to stick together. And in the dark, this is hard to do. The fish probably can’t see or smell each
other, so they may be using the FRTs to keep in touch. The sound is also emitted at a frequency that
certain predators, like sharks, are thought to be unable to hear. That would allow the fish to communicate with
each other without risk of getting eaten. But FRTs are within the audible range of mammalian
predators like seals and dolphins, so it’s probably
not foolproof. If you believe some Saturday morning cartoons, it should be possible for someone to fart
so hard, they achieve orbit. But so far, though, we have not actually discovered
any species that uses farts to fly through the air. And yes, we did check. Manatees, however, do use their intestinal
gas to move around… in the water. This is kind of, like, special amongst mammals,
though the way other marine mammals control buoyancy isn’t consistent
from species to species. Otters and seals depend on lung volume, while sperm whales may change the density
of their spermaceti organ the huge, oil-filled sac that makes their
heads enormous. But manatees, bless them, have figured out
another way. Researchers believe they use their abdominal
muscles to manipulate gas stored in their large intestine, which controls
buoyancy and helps them rise or fall in the water column. But they can also use this fart gas to steer. They keep the gas in multiple sections of
the large intestine and can move it back and forth, which gives
them control over pitch that is, horizontal rotation. Actually letting off farts helps them dive,
much in the same way that a submarine will dive when it replaces the air in its
tanks with water. And manatees have a really slow metabolism, which means they prefer not to use a ton of
energy to move around. So it’s nice to have a passive way to move
up and down. Now no one has specifically looked into how
much energy it takes to fart your way around the ocean. But researchers assume that locomotion by
fart is probably a more energy efficient way to travel short distances than,
say, waving your flippers. So, no matter how much your friends or significant
other might swear that their farts smell like roses, most of
us try to avoid smelling them. So it’s pretty bizarre to think that an
animal will use its farts to draw a crowd, but this is kind of what the southern pine
beetle does. The female southern pine beetle produces a
pheromone called frontalin. And the pheromone gets excreted with the beetle’s
poop. Yes, we’re cheating slightly on our definition
of “fart” here but the word doesn’t have a rigorously defined
scientific meaning, as far as we know. Frontalin, which is released in concert with
two other pheromones, serves a dual purpose first, it attracts male beetles for the females
to mate with. But it also attracts other southern pine beetles
in general. You see, these particular beetles are ruthless, cooperative destroyers of pine trees. They’re not super picky about which pine
trees they’ll attack any species, though in the
Southern US they prefer loblolly, shortleaf, pond pine,
and Virginia pine. Most of the time, they prey on weak and dying
trees. But sometimes, they’ll also attack healthy
ones. And if they’re going to be successful at
killing a healthy tree, they need a whole army of beetles. By themselves, a few beetles wouldn’t be
able to harm a healthy tree. That’s because the tree produces a beetle-killing
resin to keep invaders at bay, and it can make enough to hold off a small number of
beetles. But when there are a lot of beetles, the tree
can’t produce enough resin to make much of a difference, and it quickly gets overwhelmed. So the first females that arrive at their
target will release pheromones to attract a horde of beetles. Like a call to arms, but it’s a fart. Or, a poo cloud. Which isn’t better. But just when you thought the world of animal
farting couldn’t get any weirder, there’s a species of ant that appears to
use a fart-like process to enslave other ants. And no, we did not find that in a wastebasket
of rejected Ant-Man sequel pitches. It begins when a young Rossomyrmex minuchae
queen leaves the nest to start a colony of her own. But she doesn’t start the colony from scratch
or anything, because that would take too long. Instead, she takes over someone else’s colony. See, slave-making ants are just what the name
implies ants that rely on other species to do all
their hard work. Before she launches the invasion, the queen
mates with one of her own, so after the battle she can settle in and
have a lot of babies to help her control her new minions. But first, she has to get past the colony’s
defenses. A 2005 study may have figured out how she
does it. The queen carries a chemical in her Dufour’s
gland called tetradecanal. The Dufour’s gland is located on the insect’s
backside, although it’s not a part of the digestive
system. Many insects actually have this gland, including
honey bees and wasps. But it doesn’t really seem to have a common
function. Some species use it to build their nests,
feed their larva, or just communicate with other insects. Basically an all-purpose chemical factory that different species use for different things. The slave-making ant seems to use it to subdue
host ants. When the queen first enters the host nest,
her Dufour’s gland is really inflated. And by the time she’s done, the gland has
emptied out. Now that’s the extent of what researchers
have been able to observe, but here’s what they think is happening. They think the queen is secreting tetradecanal
to make her job easier. It may act as an insect repellent, which makes
the host ants keep their distance from the invading queen. It might even have an anaesthetic effect on
them. Whatever the case may be, the queen goes right
in through the front door, and the workers just kind of let her in. And a good thing for her, too, because after
she enters the colony she has to find, kill, and eat the current
queen, and then borrow her predecessor’s pheromones so the slave ants won’t recognize her as
an imposter. Which… is that like actually that so much
easier than just starting your own colony? Sounds very complicated. I’m going to kill the queen and then...wear
her skin. [shivers] Now finally, history has recorded very few
instances of directly lethal human farts. For one animal, though, farting is a literal
weapon. Apheloriine millipedes produce hydrogen cyanide
when they feel threatened. Now this is not exactly like a human fart, since it doesn’t come out of the same orifice,
or even near that same orifice. Still, it’s a pretty extreme way to weaponize
a naturally-produced gas, so consider it an honorable mention to round
out our list. These millipedes shoot cyanide out of glands
called ozopores, which are located all along their bodies. This stuff is so toxic that one millipede
could, in theory, use it to mow down 18 pigeons… at a time. This is a weirdly specific number to have
come up with, but it is derived from how much gas comes
out of the millipede and how much cyanide it takes to kill a pigeon. So like the worst fourth-grade word problem
ever. And it gets weirder, because while the millipede
is effortlessly murdering 18 pigeons, it remains itself totally
unaffected by the cyanide. Researchers used to think that the millipedes
had to hold their breath or something to avoid being killed by their
own poison. But as it turns out, millipedes are actually
immune to cyanide. Cyanide is lethal because it deprives cells
of oxygen. But it does not do that to millipede cells. Because if any of the stuff blows back in
their direction, the millipedes’ bodies are capable of turning it into a harmless
chemical called β-cyanoalanine. This millipede doesn’t have a lot of natural
enemies, obviously, because practically no one is going to mess
with you if actual cyanide comes out of your body. There’s only one creature that dares to
prey on it a certain species of beetle that incidentally also appears to be resistant to cyanide. So… is there a moral to this story? Well, if anything, it’s that we might joke
about farts, but various gases expelled from various rear-adjacent
parts of the body can have many useful functions
for a wide variety of organisms. Because nature is just that diverse. It’s also possible that we’re just searching
for a teachable moment, when really we just wanted to talk about farts. If you enjoy this particular style of episode,
I have some good news: We have a podcast for all the stuff that we
can’t talk about on our main channel. It’s called After Hours, and in it, we dig
up some seriously weird, also fascinating but also pretty unsafe-for-work science, and have some fun with it. It’s available as a perk for our patrons
at the $4 level or higher. So any amount over $4 and you get SciShow
After Hours every month. So if you’d like to support SciShow, and
learn about some of the stuff that’s in our R-rated folder, check us out
at patreon.com/scishow. You get all the future ones, but also all
the ones we’ve already done so you can listen to a bunch of them. And have your mind be absolutely blown by how weird and kinda messed up the world
can be. [♩OUTRO]
