- [Narrator] In nature,
food rarely comes easily. Some forms of prey out there have developed pretty
terrifying defense techniques to avoid becoming dinner. But apparently, nature's
most hardcore animals just don't care. From creatures with an
appetite for the poisonous and the spiky, to some unexpected fans of all things bony and rocky, get ready for the
animals that have evolved to eat deadly food. (upbeat music) Turtle wipeout. Turtles may be one of the
ocean's cutest animals, but these reptiles feed on a
surprisingly dangerous diet. And no, I'm not talking
about oceanic plastic. The leatherback turtle, found
in the Atlantic, Pacific, and Indian Oceans, regularly
eats stinging jellyfish, even occasionally including
the box jellyfish, which possesses some of
the most potent venom in the animal kingdom. The tentacles of the box jellyfish are covered in tiny, toxin-filled cells called nematocysts, and any poor fish that comes into contact
with the deadly tentacles are usually instantly stunned,
killed and eventually eaten. In humans the box jelly's sting causes excruciating pain
on the point of contact, leading to a drop in blood pressure, difficulty breathing
and even heart attacks. Leatherback turtles, meanwhile,
have no such problem. Thanks to their thick skin, particularly around their beaks and an armored shell,
these turtles are able to munch on jellyfish
without having to worry about any flailing tentacles. To provide extra safety while
dinner is on the way down, hundreds of small spiny projections called papillae are lined all the way from the turtle's throat
down to their gut, maybe turtles aren't so cute after all. These thick, resilient, semi-soft prongs help to grip the jellyfish,
and give the turtle's esophagus an added cushion from any stings. All stings considered,
even the deadliest jellies end up as a pretty safe snack
for leatherback turtles. Getting hungry yet? Luckily, we've got tons of videos for you to sink your teeth into,
so don't forget to hit those like and subscribe buttons, and ring the notification
bell too, for dessert. Now where were we? (whooshing) Rock-hard stomachs. Recently, a new species
of the shipworm mollusc was discovered in the Philippines, known by the locals as the antingaw, with a super weird trait. Typically, shipworms, which
usually grow between eight and 18 inches, are known
for gnawing into wood found in water, which has caused sailors some serious trouble over the years. In 1503, these pesky
molluscs chewed through and sank at least two of
Christopher Colombus' ships as they ventured for the Americas. But incredibly, the
newly-discovered species of shipworm munches through something even more
indigestible than wood. Their go-to-dish is limestone rock. Now, obviously, humans eating
rocks would be an awful idea, given rocks' indigestibility, and choking and laceration hazards as they slide down your throat. But it's worth noting that other animals are known to swallow rocks
to aid with digestion. Some birds, such as ostriches, swallow rocks and store them
in a part of their stomach called the gizzard. The muscular gizzard contracts, grinding the rocks against
their stomach contents to break down their meals, making up for their lack of teeth. But even these brave birds aren't capable of actually digesting rocks. And even if they were able
to break down limestone, for example, it's made
up of calcium carbonate, a chemical compound that would
likely cause stomach pains, nausea and vomiting if ingested
in large enough quantities. But bizarrely, antingaw
shipworms not only burrow into limestone; they ingest it too. The molluscs have thousands
of specially-adapted flat teeth, designed to help
grind down the limestone into digestible chunks, before eventually pooping it out as sand. However, nobody knows
why the worms do this, as they don't appear to
gain any nutritional value from the limestone, instead
getting their nourishment from bacteria found in their gills. Whatever their reasoning,
if you have some antingaws over for dinner, forget key lime pie, these guys are hungry for limestone, just let me know if you get a chance to ask them exactly why. Bone-eating vultures. If you enjoy food with
a bit of crunch to it, you'd probably get along great
with the bearded vulture. These birds, found
throughout southern Europe, Africa, and western Asia, have a diet that's 70-90%
consisting of bone. Instead, bearded vultures crave bone, particularly the marrow inside
due to its high fat content. They've learned to crack large
bones by carrying them up a dizzy 500 feet in the air, before dropping them on the rocks below. The vultures then extract that hearty, nutritional marrow from the bone shards. What's more, these
vultures are even capable of swallowing bones whole to ensure they get their fix of marrow. While canines chew through
the odd bit of cartilage here and there, bones are indigestible for pretty much every other animal. Luckily, these ballsy birds
have evolved stomach acid with a pH of an extremely corrosive 0.7. Their sour stomachs not only
help with dissolving bones, but also protect these
birds and other vultures from harmful bacteria, like salmonella, that are found on rotting animal carcasses that vultures scavenge. Impressive, but remember
they still have to swallow the bones in the first place. There's a good reason no other
animals regularly do this. Whether it's the risk of choking, or the threat of piercing internal organs with sharp edges, bone-eating
sounds like a miserable meal. Not that bearded vultures care. Their elastic throat is able to stretch to help swallow remains
of all shapes and sizes. The inside wall of the
throat is also thicker than those of other animals, preventing any piercing from sharp edges. As they say in France, bone appetit. Long Necks, Unusual Tastes. It's not just vultures who
have a taste for bones. In a bizarre, unexpected twist, it may surprise you to learn that despite usually being herbivores, giraffes also feed off carcasses, supplying their diet with
calcium and phosphorus, to grow and strengthen
their enormous skeleton. While these deceptively-hardcore
African mammals don't actually swallow bones,
they chew and lick them, using their saliva to dissolve all the nutrients they need. I'm not sure if that's
less or more disturbing than just gobbling the bones up. If you thought bones were brutal, wait until you hear about
giraffe's other favorite treat, the deadly acacia tree. Over time, this tree has
developed a devilish defense in an attempt to restrain
animals from grazing on them. The razor-sharp thorns
of this terrifying tree can be four inches long, and unless an animal's looking
for a facial acupuncture, they're usually best to stay away. However, giraffes have a sticky solution. Using their thick lips
and long, flexible tongue, coated in gloopy, protective saliva, the giraffe can remove
most of the sharp thorns from acacia branches, before munching away at the twigs and leaves. But the battle doesn't stop there. The acacia tree releases
bitter-tasting tannins when eaten, which can
bind to digestive enzymes, affecting an animal's
ability to gain nutrition from food, and proving
toxic in large quantities. In 1990, 3,000 antelope died after heavily grazing on
acacia trees in South Africa. So, what about the giraffes? Don't you remember I told
you they were hardcore? Their saliva contains
tannin-binding proteins, effectively neutralizing
the tannins' toxic effects. Only problem is, all the saliva that these massive mammals produce can lead to gallons of giraffe drool. Unfortunately, though, drool isn't the only gross bodily fluid that provides a vital, yet
weird uses for giraffes. Their urine has some
even stranger functions. Revolting as it may seem, male giraffes are willing to swallow a mouthful of a potential mate's pee to determine whether she's fertile or not. Yeah, pal, I think I'd pull
that face too in your situation. As funny as it looks though, that hilarious pout's
actually the giraffe's way of aerating the urine to
analyze it more fully. Courting a non-fertile female giraffe with no chance of producing offspring would waste too much energy, so it's quicker to just
swallow a mouthful of pee to test for ovulation. And they say chivalry is dead. Spiky supper. Giraffes aren't the only animals who can't get enough of the sharp stuff, be it urine or bones. The menacingly named wolf eel
loves to munch on sea urchins. If you didn't know, sea urchins are completely covered
in protective spines, often laced with a venomous kick, to prevent themselves from
becoming someone's lunch. For wolf eels roaming
the waters of the Pacific and Atlantic oceans, those
spines don't scare them off. They're able to eat these spiky meals thanks in part to their large, puffy lips, which soften the blow of the spines, allowing their powerful jaws to crunch through
urchins' tough outer layer to the meaty goodness inside. This is all made easier
thanks to their huge, intimidating teeth, which
also line their throat for extra grip and crushing power. Those bizarre throat teeth
also provide an easy way to turn urchin spines,
venomous or otherwise, into little more than a
fine powder on the way down, avoiding any nasty surprises
when digesting them. So, considering this creature
eats spiky death spheres for fun, you'd better
make sure no part of you ever ends up anywhere
near a wolf eel's mouth. Fatal feasts. When you think of a tasty snack, I'm sure newts aren't
near the top of your list. The North American garter
snake, on the other hand, frequently feeds on newts,
especially when it comes to the rough-skinned kind variety. However, not only does this amphibian sound unpleasant to eat, it's also an extremely dangerous snack. This noxious newt harbors a
poison, known as tetrodotoxin, or TTX, in the glands on its neck. Just one rough-skinned newt can contain up to 15
milligrams of the stuff, and it only takes one
milligram of the toxin to kill a human. TTX binds to membranes inside bodily cells called sodium channels, interfering with the
transmission of signals from nerves to muscles. This halts the ability
to control nerve impulses to perform actions, like
contracting muscles. When consumed, even small amounts of TTX can lead to vomiting, diarrhea
and extreme paralysis. You'd think that would be enough to put the gutsy garter snakes
off, but you'd be wrong. So how are they able to
enjoy this forbidden snack? Well, to combat these toxins, the shape of the snake's sodium channel has changed over time through evolution. This way TTX does not bind to their sodium channels as easily, building up the snake's
resistance to the toxin. It would take around 100 milligrams of TTX to be considered deadly for garter snakes, which is the equivalent to
seven whole newts in a row. So, unless these slithering
serpents over-indulge on a rough-skinned newt buffet, they'll be fine eating these toxic treats. But newts aren't the only deadly snack that can take a snake's fancy. Some serpents have been seen
eating, well, themselves. Yes, you heard that right. As snakes are cold-blooded animals, they're not capable of
controlling their body temperature through things like sweating or panting. So, a snake looking to top up
its tan can quickly overheat, affecting the way a
snake's brain functions and leading to confusion. As a result, they occasionally
become excessively hungry, and mistake their own flicking
tails for a prey animal. If they don't cool down
and come to their senses, snakes can actually eat
themselves to death, either through blood loss,
infection, or suffocation. And the rest is hissssstory. The rat's revenge. Snakes aren't the only
animal to develop an appetite for deadly amphibians. The rakali, otherwise
called the water rat, is known for making a meal
out of poisonous cane toads. If a human were to chow
down on one of these toads, the ingested poison, called bufotoxin, would initially cause
vomiting and diarrhea, and within an hour, the
symptoms would intensify. The heart may begin to beat irregularly, failing to pump blood around the body, possibly proving fatal. As the conniving cane
toad was only introduced to Australia in the last century, many native animals there haven't adapted to these poisonous powers either. For example, since the
introduction of cane toads in the 1930s, the population of yellow spotted monitor lizards, a predator of the cane
toads, has dropped by 90% due to fatal feasting
on the poisonous toads. But, unlike these lizards, Australia's native rakali water rats won't go down without a fight, or a feast. They've devised an
ingenious method to snack on the devilish toads, without
the deadly side-effects. Now, I'm just warning you, this is about to get pretty hardcore. To feast, the water
rats flip the toad over, before slicing the chest
open with their teeth. They do this to target
the least poisonous parts of the cane toads, removing
and eating the heart and liver. Sort of like nature's
version of "Operation". This way, the water rats avoid
ingesting too much bufotoxin, which is mostly found
around the neck glands and on the skin. That takes the saying eat your
heart out to the next level. Boozy shrew. Not all the dangerous meals of nature look hazardous at first glance. Take the Bertam palm tree. This flora, found in the depths
of the Malaysian rainforest, doesn't look too dangerous, does it? But beware, the potent
nectar of this tree's flowers is capable of intoxicating humans. Though, not quite in the same
way as we've seen so far. The flowers of the Bertam palm naturally contain populations of yeast, and this yeast ferments the palm's nectar, which ends up possessing a
3.8% alcohol concentration, the same as a light beer. The pen-tailed tree shrew has
a love for this boozy nectar, and despite only weighing a few pounds, these little guys drink the equivalent, adjusted for their tiny body weight, of 10 glasses of wine per night. If a human were to consume as much alcohol as the pen-tailed shrew every night, it would quickly cause
liver disease, heart failure and alcohol poisoning,
possibly even death. The shrews are unperturbed, however, and seek out the pungent, yeasty nectar due to its high sugar levels. You'd think the boozy behavior
of pen-tailed tree shrews may lead to them stumbling
around the jungle, or wishfully texting their crush. However, the small shrews
show no ill-effects from ingesting the alcoholic nectar, not even appearing to get drunk. So what's their secret? It's all down to the shrews ability to effectively modify alcohol toxins into less toxic substances. The tree shrew converts much
of the alcohol they ingest into a non-intoxicating
by-product of alcohol called ethyl glucuronide, or EtG, which ends up in their fur. Turns out they're much
more effective at this than other mammals, like us. As such, the hairs of
the pen-tailed tree shrew contain 30 times the amount of EtG that would be present in a human that drank alcohol excessively. And here we were thinking
us humans had the monopoly on drinking booze. The boozy pen-tailed tree shrew, now that's a real party animal. Massive Mouthfuls. How do you like your eggs in the morning? With a kiss, boiled, scrambled? Probably not swallowed whole. Unless you're an egg-eating snake. Yes, these toothless reptiles
feed exclusively on eggs, swallowing their meals whole, even when the egg is
four to five times wider than the snake's mouth. The snake's jaws are not
fused together like ours, instead being connected
by an elastic ligament, allowing their mouth to open 150 degrees. It's then a slow process of
forcing their stretchy body over the egg, check it out. (birds chirping) While this process is going on, snakes use a moveable
opening in their mouth called a glottis to breathe, which can be maneuver
around to enable airflow, despite the huge mouthful. After the meal has been
successfully swallowed, egg-eating snakes rely on strong muscles and bony protrusions in their spine, which puncture and crush the eggshell, releasing the contents for digestion. Man, I'm struggling to breathe
just thinking about it. Similar to snakes, frogs also
swallow their food whole, but rather than eggs,
they usually favor insects and other small prey. Most frogs have no teeth either, but rather than widening their jaws, they, strangely, use their
eyes to help swallow food. When the prey is in the frog's mouth, their eyes retract,
providing additional force to guide the unfortunate
victim down the frog's throat. Thanks to the fact that frogs can breathe through their skin,
choking is rarely an issue, so a big meal is always on the cards, though, maybe not quite like
the one attempted in this clip. - [Woman] Oy, oy, no, Billy. - [Narrator] But in the case
that a frog does fully swallow something too big, or
something that proves poisonous or troublesome, the
amphibians have developed an unbelievable response. Forget vomiting, frogs and
toads, for that matter, eject their whole stomach. Their front feet wipe
away the unwanted prey, before they swallow their
stomach back up again, and all because they don't
have the ability to vomit in a conventional sense. I've never considered it
before, but man am I glad we humans can throw up,
and not have to go through what frogs do. But it's not just reptiles and amphibians with the unique tools to handle
their big, big appetites. The black swallower
fish is found at depths of over 2.5 miles in the Atlantic Ocean, and is the true king of
All-You-Can-Eat buffets. Food is so scarce in the deep sea, that when the black swallower
eats, it has to feast. With large, flexible jaws,
it swallows large fish whole, into a stomach so stretchy
that it can ingest food twice its own size and
ten times its weight. Even still, its eyes can sometimes
be larger than its belly, and that's saying something. Occasionally, determined prey can bite or pierce holes through the black swallower's stretchy, yet thin stomach, killing the greedy fish in the process. What's more, if they eat a meal too large, the fish inside the stomach can decompose before the swallower has
had time to digest it. Gas released from the decomposition can force the black swallower to float up to the ocean surface, where it dies due to the
severe changes in pressure upon its body. Sometimes, it really
does seem like evolution, or God, whatever floats your boat, only half-planned out the bodies of some of the creatures on Earth. Gassy worms. At even lower depths than where
the black swallower binges, live giant tube worms. These creatures somehow survive
along hydrothermal vents, 8,000 feet below the
Pacific Ocean's surface. These vents spurt out
seawater heated by hot magma, the released fluid reaching a
spicy 700 degrees Fahrenheit. Fortunately for the giant tube worms, the near-freezing sea
water in the deep ocean quickly cools the temperature of the fluid ejected from the hydrothermal vent before it can damage them. It's one thing to not get burnt, but what exactly can
something eat at such depths? Well, giant tube worms have no mouth, and don't technically eat at all. Instead, they have what's
called a trophosome, an organ filled with bacteria which provide them with energy through a truly bizarre means. The hydrothermal vents
around which the worms live emit a high concentration
of hydrogen sulfide. This gas is toxic to most
animals, including humans. Exposure, even to low levels, of hydrogen sulfide will burn your eyes, and if breathed in, can cause headaches, memory loss and severe nausea. Luckily for the tubeworms, the bacteria inside their trophosomes use the hydrogen sulfide
as an energy source, through a process called chemosynthesis. This typically converts hydrogen sulfide, water and carbon dioxide into glucose, which the tubeworm then feeds off. With such a gassy diet, maybe it's best that they're 8,000 feet below the surface. A koala-ty snack. With their lovable looks, you'd never expect that
Koalas indulge a deadly diet. But it's true, and it all
comes down to eucalyptus. For most animals, feasting on the leaves of the eucalyptus tree
isn't a risk worth taking. The leaves of the plant
contain eucalyptol, a substance that in
its pure form is deadly to humans in doses as
small as 3.5 milliliters. Considering that koalas
get through about 500 grams of these leaves per day, you'd
hope that they've evolved to ingest the toxic leaves. And, technically, they have, but it's a little more complicated, and frankly, bizarre, than that. Koalas possess an unusually large presence of detoxifying enzymes, useful gut bacteria, and a very well-adapted digestive system, allowing them to break down
and flush out eucalyptol toxins that would normally be
deadly to other animals. However, in a head-scratching twist, baby koalas aren't actually
born with this ability to safely digest eucalyptus, despite it being almost all they eat. Before the baby koala can
feast on eucalyptus leaves, they need to feed on pap. Sounds fine, but wait. Pap is, poop, from mommy koala. But not any old poop. This is a mushier form of excrement, which is vital to the joeys development, containing the crucial
gut bacteria required for safely digesting eucalyptus. And you thought human baby food was gross. Cacti-eating camels. Whether it's the desert's scalding heat, or the lack of food and water, only the strongest animals survive. Just take the camel. Not only are these stubborn guys able to withstand the ferocious
rays of the desert sun, they've evolved to find food
where there doesn't seem to be any. But there's food there, all right, as long as you, like a camel, are happy eating viciously-spiked cacti. The threat of having six-inch thorns pierced around your face is
enough to put most animals off messing with these succulents, but camels are perfectly suited to tackle such a prickly plant. Their mouths are full
of cone-shaped papillae, somewhat like those [99]found
in leatherback turtles. For camels, the resilient,
flexible papillae prevent most of the cacti spines from piercing the more
tender parts of their mouth. While eating chunks of cacti, camels orient them at
the side of their mouth, rather than trying to
swallow them straight down, making the sharp spines
much more manageable. Still, it's a lot of work,
and if an opportunity for an easier meal comes along, the camel will take full advantage of it. As you can see in this next clip. (shouting) (speaking foreign language) Now that might seem rather rude, but it's certainly easier
than cactus cuisine. Even so, if there are no humans
with loaves of bread around, a desert cactus will do just fine. Unfortunately, though, not all animals have evolved such ingenious
cactus-eating techniques. Take cats for example. Despite having no good reason for trying, countless cats have been
witnessed by their owners nibbling on cactuses. If you ever happen to see
your little feline friend sampling a cacti, don't be too alarmed. They're most likely bored,
testing out new textures for fun. But to be safe, try to make sure your cat has plenty of sources of
mental stimulation available, and keep your cacti out of reach, just to make sure your cute kitty with camel-like aspirations doesn't get a spiky meow-full. Which of these animals' deadly
diets shocked you the most? Let me know in the comments below and thanks for watching.
