A desert lynx showing its teeth angrily


1. About half of all koalas have chlamydia

While this little cutie may look like he’s sleeping peacefully, chances are the koala is suffering from chlamydia. Scientists believe that somewhere around half of all wild koalas (or more) have the sexually transmitted disease. Koala chlamydia is actually caused by two different bacteria strains.

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The most common strain in Queensland, Australia can’t be transmitted to humans but the second kind can. For example, if and when a koala pees on someone. Antibiotics can’t treat koala chlamydia as they can for humans because it messes with the koala’s gut microbes, interfering with their ability to digest eucalyptus, and thus causing the animal to starve.

2. This cat imitates baby monkeys to lure in parent monkeys and eat them

Deep in the Amazonian jungle, a high pitched squeal that vaguely sounds like a baby pied tamarin monkey comes from within the brush. A pair of adult pied tamarins inch closer for a better look — is it a baby unattended and in need of help? Nope, a cat leaps out and takes down one of the monkeys, eating it.

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This cat is the margay, a tree ocelot. It lives in the trees of Central and South America, hunting mammals like squirrels, rabbits, and small monkeys. But while the margay is tricking monkeys, people are threatening it with habitat destruction, the exotic pet trade, and deadly guns.

3. Hamsters are little alcoholics with insanely high tolerances

Whenever Syrian hamsters are offered a choice between water and alcohol, they always choose alcohol. In fact, alcohol researchers regularly use them as guinea pigs (lab rats?). But even if the hamsters consume copious amounts of alcohol, they don’t get drunk (scientists used a “wobbling scale” to determine their drunkenness).

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So, why do hamsters have such a penchant for alcohol and high tolerance to its effects? Well, they like to bury fruit for the winter. During the months of sitting underground, the fruit ferments and turns alcoholic. Hamsters find their stash by the scent of alcohol and have developed quite a liking for it. As a result, a hamster’s liver is huge!

4. Mama penguins kidnap chicks (and usually abandon them to die)

If you’ve seen March of the Penguins, you know that emperor penguin mothers go on a two-month-long journey every year after laying their single egg. They waddle and toboggan all the way to the ocean for food and then turn around and go all the way back. This entire time, the female is full of the parental hormone prolactin.

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Once she gets back to the colony of penguin dads and chicks, she might find out that her baby died while she was gone. And since the hormone is still flowing through her blood, she might turn to a life of crime and kidnap another penguin’s chick. In some cases, the real mother gets her chick back, but usually, the baby ends up abandoned and dying from the cold.

5. Adorable wombats knock people over and maul them

While wombats have adorable faces that make you want to pinch their cheeks, you must remember that they live in Australia. And, as with most things that live in Australia, they are very dangerous. Australian zookeepers know that wombats are only second to lions and bears when it comes to danger.

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Sure, young wombats are adorable and cuddly, but once they grow up, they become solitary and aggressive. For instance, if a dingo invades a wombat’s burrow, the wombat will lift the animal on its back and squash it against the ceiling. They sometimes charge humans, knock them over, and viciously bite the person.

6. Female Adélie penguins mate for nesting material

Adélie penguins are one of two species of penguins that live in Antarctica. Down in the cold, they make super “comfortable” nests out of rocks. But apparently, good nest rocks are hard to find, so the penguins briefly mate with their neighbors to get more.

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NOAA Photo Library

Crafty penguins will steal stones from another’s nest, but some females have come up with a method of trading: they waddle on over to another male’s nest, mate with him, take a stone, and then waddle back to their nest and unsuspecting mate. The cheekiest and smartest females will begin a courtship ritual, then grab a stone and run off before they even mate.

7. Dominant meerkats murder babies and force the childless mothers to nanny their kids

Meerkats may look adorable but their social life is something akin to Game of Thrones. An alpha male and female rule over about 50 meerkats, restricting their reproductive rights and controlling which jobs each meerkat does. Sometimes, a subordinate meerkat will give birth, but the alpha female is sure to make her regret it.

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Hans Hillewaert/Wikimedia Commons

She will kill the meerkat babies and then give their mother two choices: leave the safety of the colony or take care of her babies, even though she just killed their offspring. Low-level females nurse the alpha pair’s young and even have to risk their lives for them when predators come around.

8.  Sugar gliders are driving a species of parrot to extinction

Sugar gliders may look like adorable nut-munching critters, but they’re actually driving a species of parrot to extinction. The gliders are originally from Australia, but they were introduced to Tasmania where they mostly eat female swift parrots. As a result, there are three times more male swift parrots than females.

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Normally, these parrots are monogamous, but now females are spending way more time giving attention to multiple males (who feed them in exchange for sex) and less time caring for their chicks. The chicks are dying from lack of care and sugar gliders are eating about 50 percent of the female parrots each year.

9. Polar bear males are cannibals

Aren’t these polar bear cubs adorable? So cute you could eat them up? That’s what male polar bears think in late summer and autumn when seals in the Arctic are scarce. There’s almost nothing to eat, so the male bears go after defenseless cubs. The cub’s mother will usually try to protect her baby, but she’s much smaller than the average male and won’t be able to fight him off.

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Since climate change is making seal-hunting harder, polar bear cannibalism is likely becoming more common. In one case, a male ate an entire pregnant female. And while females are usually hungrier than males (from nursing their cubs), they don’t go around eating babies.

10. Fur seals are assaulting penguins

Way down in the sub-Antarctic, some truly horrific things are happening between fur seals and penguins. On multiple occasions, these young male seals have forced themselves on king penguins after first chasing them down. These encounters lasted about five whole minutes.

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After one of the four observed encounters, the seal killed and ate the penguin. Yikes. Normally, fur seals are penguin predators, so these sightings left scientists wondering what was going on. These seals were young and too small to fight for the chance to mate with a female seal, so perhaps they were practicing or letting out their pent-up frustration.

11. Great tits steal the homes of other birds and eat their brains

Normally, great tits (the bird pictured below) eat things like bugs and seeds. They also steal food from other birds’ stashes, pick at the bones of hoofed mammals, and, once upon a time, ate hanged people. But this isn’t where the debauchery stops. Sometimes, they turn into murderous, brain-eating monsters.

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For example, in northern Europe, pied flycatcher birds are returning to their nesting sites to find great tits, who then attack them and eat their brains. And while that slaughter seems to be due to climate change, great tits have also been caught pecking open the heads of bats. The bats only die once the pointy little beak reaches their brain.

12. Male Adélie penguins engage in necrophilia

So this scientist named George Murray Levick visited the Antarctic around 1912 and wrote down all his observations of Adélie penguins. But he saw some things that (to him) were so depraved he wrote the notes in Greek, so only people in higher education could read about the sex lives of the penguins.

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Liam Quinn/Wikimedia Commons

What was he so shocked by? Well, some male penguins try to mate with female corpses. In fact, a modern researcher wanted to know just how far these penguins will go, so he presented them with a frozen penguin head and a rock for its body. The males attempted to mate with it. It seems that these penguins get turned on by a specific female posture, so whenever they see that, they just do what they gotta do.

13. Bunnies can get pregnant within minutes of giving birth

Bunnies are known for “breeding like rabbits.” At just three or four months old, rabbits can start breeding. It only takes about a month for an entire rabbit pregnancy and then within minutes of giving birth, a female rabbit can be impregnated yet again. Surely any woman with a kid will understand the horrors of that situation.

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Theoretically, a single female rabbit and all her offspring could make 184 billion rabbits in seven years (the average rabbit lifespan). Of course, since the world isn’t overrun with bunnies, this isn’t happening. So why is that? Rabbits don’t actually breed all year long, only when the weather and food supply are optimal.

14. A Canada jay tore a baby bat from its mother and ate it

This adorable little bird may warm your heart with its fluffiness, but it’s one of the most fearless birds in North America. They nest in the winter, as opposed to spring, and will eat just about anything they can find. One was even seen ripping a little baby bat from its mother and then eating it.

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Canada jays also raid nests of other birds and even eat smaller birds. Then, after getting their food, they store it in a truly unique way: under a glob of sticky saliva on a tree. They hide it under lichen or in-between conifer needles and are quite good at remembering where they left it. When the birds are young, the dominant sibling kicks its brothers and sisters out of their territory.

15. Male lions kill cubs to get females ready to mate

If the Lion King were real, Scar’s motivations to kill Simba would not be to take out the prince and successor to the “throne” but rather to knock up his mom. Yes, that’s right, male lions like to engage in infanticide (the killing of young) when they take over a pride — to mate with the lionesses.

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Mother lions care for their cubs for about a year, during which they are physically incapable of getting pregnant again. However, if something just happens to take the cub out of the picture, the lioness will go back to ovulating. Then, the male lion can start spreading his own genes.

16. Prairie dogs are serial killing ground squirrels

While this pudgy cutie is a strict vegetarian, he’s also a vicious killer. Living in the plains of Wyoming, Utah, and Colorado, white-tailed prairie dogs compete with ground squirrels for plant-based foods. But they are savage about it. Think Dothraki horde descending on a small farming town and you’ll get an idea.

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USFWS Mountain-Prairie/Wikimedia Commons

Scientists watched as prairie dogs chased ground squirrels down, stalked them, or waited outside their burrow before using vicious bites to kill the competition. Each prairie dog has its own preferred method of killing. Some even snatch babies out of their underground dens. It turns out that prairie dogs who serial kill have higher fitness than their less-murderous friends.

17. A serial killing swan couple took their baby to see the victims

Swans may embody the words “beauty” and “grace” on a regular day, but Hannibal and his mate Mrs. Hannibal wreaked havoc in Wales when they murdered at least 15 other swans. The two lived alone in Castle Pond with their baby, but whenever another swan strayed into their territory, things took a disturbing turn.

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Hannibal would either drown the visitor or peck its feet into bits while Mrs. Hannibal kept the victim from escaping. Once they were done murdering, they brought their fluffy little baby over to view the corpse as they raised their wings in celebration. Oh, and one time a different swan knocked a man out of his kayak and kept him from swimming to shore, drowning him.

18. Hamster moms eat their babies (sometimes)

Have you ever stared at a hamster and its adorable pudgy cheeks, wondering what dark secrets lie behind its inscrutable black eyes? Perhaps the hamster merely munched on tiny food with itty bitty hands, not telling you that if it came down to it, she would eat her own babies.

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Like human first-time moms, giving birth and raising kids is incredibly stressful for hamsters. So sometimes hamster moms kill one of their babies. And eat it. Other times, she does this if there isn’t enough food, water, or space for her whole family. Plus, if her own diet is very poor (like wild French hamsters eating exclusively corn) she’ll eat her babies for their Vitamin B.

19. Male antechinuses mate so hard and so much they disintegrate

“Go hard or don’t pass your genes on to the next generation,” one male antechinus probably said to another, the day before they embarked on their three-week sex marathon. Their bodies have recently stopped making sperm, so this is their once-in-a-lifetime chance to make babies. As many babies as possible.

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For the next two or three weeks, male antechinuses spend all their time mating. They do it as much as possible until their bodies start to literally fall apart: internal bleeding, gangrene, blindness (you know, the works). At the end of it all, females are running away from these near-zombies, until finally, they drop dead.

20. Dolphins murder porpoises and engage in “calf-tossing”

We’ve already got a taste of the dark side of dolphins, but if you need another reason to be wary of them, there’s more. Scientists got a hint of this when dead porpoises and young dolphin carcasses began washing up on beaches. They had severe injuries from blunt-force trauma.

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Researchers had seen adult dolphins “calf-tossing” — an alarming form of infanticide. In fact, the first time scientists ever saw a bottlenose dolphin give birth, two males came and tried to drown the baby almost immediately. They likely do this for the same reason as lions: to make the female ovulate. As for the dead porpoises, that’s less clear.

21. Tasmanian devils give each other mouth cancer

These adorable marsupials are truly unique, but they’re also heading straight for extinction. You see, Tasmanian devils love biting each other right on the face, which would be all fine and dandy except that they also happen to have a form of contagious cancer. It’s called Tasmanian devil facial tumor disease and it’s truly grotesque.

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The tumors grow on their faces or in their mouths, getting steadily larger until they kill the poor thing. The disease is threatening Tasmanian devils with extinction, but the devils just can’t help but bite each other. Whether it’s fighting over food or mates, they keep spreading the disease.

22. Koala babies eat their mom’s poo

Alright, we’ve already covered koala chlamydia, but the cutesy koala has a few other weird things it’s hiding behind its sleepy face: koala babies eat their mom’s poop. Why, you ask? Well, the problem is that koalas only eat eucalyptus leaves, which are quite toxic.

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Adult koalas have microorganisms in their stomachs to help digest the eucalyptus and rid them of toxins, but the babies don’t have these microbes yet. So, as a solution, baby koalas eat liquefied mom feces called “pap” (after they’re off the milk). Oh and sometimes the adults will throw up in their own mouths to chew a second time.

23. Hedgehogs also eat their babies (sometimes)

Similarly to hamsters, mother hedgehogs sometimes eat their little pink babies. For pet hedgehogs, it usually seems to be a case of fright — don’t you eat people when you’re scared? The problem is, hedgehogs get scared very easily by just about everything. They haven’t been kept as pets for very long, so they’re not well adapted to life with humans.

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In order to keep the hedgehog mom from eating her young, veterinarians suggest keeping people and other hedgehogs away from the mother for several days before and after she gives birth. Ideally, this will keep her from a life of cannibalism.