Top 10 Creepy Animal Facts That Will Keep You Up at Night
Top 10 Creepy Animal Facts That Will Keep You Up at Night

Top 10 Creepy Animal Facts That Will Keep You Up at Night

VOICE OVER: Rebecca Brayton WRITTEN BY: Caitlin Johnson
Mother Nature can be a cruel mistress. For this list, we're looking at the strangest, grossest, and most unsettling parts of the natural world. Our countdown includes Koalas Have Chlamydia, Leeches Can Grow to Be Huge, Cockroaches Are Nearly Invincible, and more!

Top 10 Creepy Animal Facts That Will Keep You Up at Night

Mother Nature can be a cruel mistress. Welcome to WatchMojo and today we’ll be counting down our picks for the Top 10 Creepy Animal Facts That Will Keep You Up at Night.

For this list, we’re looking at the strangest, grossest, and most unsettling parts of the natural world.

#10: Tears of Blood

There are several different species of horned lizards that possess the remarkable ability to squirt blood from their eyeballs. But they don’t just do this for fun, it’s a defense mechanism. When faced with a large predator – a coyote, for example – the lizard’s ace in the hole is shooting blood straight into the mouth of whatever is trying to eat it. Apparently, the blood tastes so foul to the lizard’s usual predators that it will make them back off and find a different meal. The lizard does this by bursting the blood vessels in its eyes. It may be bizarre, but if it works, it works!

#9: Koalas Have Chlamydia

Australia has no shortage of weird and wonderful wildlife, and one of its most famous creatures is the cuddly koala. But you may get more than you bargained for if you ever pet one of them; adorable as they are, huge numbers suffer from the STI chlamydia. It spreads from sexual activity but can also be transmitted when baby koalas eat their mothers’ feces, or “pap”, because at such a young age, they’re not yet able to consume eucalyptus leaves – they have to eat them once they’ve already been digested. But it’s not all doom and gloom; scientists are working hard to save the koalas and have even begun to trial a chlamydia vaccine for them.

#8: Beaver Castoreum

Though their dams can sometimes be mislabeled as a nuisance, beavers have been incredibly useful to humans over the years. One of the strangest uses involves a secretion known as “castoreum”. “Castoreum” comes from a beaver’s castor sac, which is located near the animal’s anal glands. Along with urine, the beaver uses the scent to mark its territory. But the goo has been used as a perfume tincture to make “leathery” scents, and even as a food additive - especially in vanilla. Fortunately, because it’s difficult and expensive to acquire, today you’ll only find it in extremely high-end luxury goods.

#7: Ladybugs Eat Their Young

They may be cute and beloved by kids around the world, but ladybugs are just one of many animals to routinely engage in cannibalism. Researchers have found that ladybug larvae often kill and eat one another for a fast meal, and that those who do this are more likely to grow into adulthood. Adult ladybugs are also known to eat eggs or larvae as well. Equally brutal are meerkats; female meerkats are known to kill the offspring of other females to give their own kids a better chance, and will bully bereaved mothers into becoming wet nurses for their own young.

#6: Leeches Can Grow to Be Huge

These gross bloodsuckers are unpleasant no matter what size they are. But the biggest leeches in the world are actually enormous! The world’s largest species resides is in South America. The giant Amazon leech can grow to be 1.5 feet long and 4 inches wide, getting larger the more blood it drinks. Remarkably, it was also believed to be extinct for eighty years but was rediscovered in the ‘70s. In 2015, images went viral showing someone feeding a pet leash with their own arm. That’s definitely devotion - but yikes!

#5: Electric Eels Can Jump

In the 1800s, a strange legend emerged from one naturalist’s travels in South America: electric eels had been seen jumping out of the Amazon river to attack horses. This was thought to be a myth until electric eels in captivity were observed and filmed doing exactly that in 2016. Luckily for us, this seems to be a behavior that they’ll only employ if they’re on the defensive. They leap from the water and then discharge powerful electric shocks, pressing themselves to the predator to ensure maximum pain; these out-of-water shocks are stronger and more unpleasant than the common, underwater ones.

#4: Sea Cucumbers Expel Their Organs

Though they can be served up and eaten as a delicacy, few creatures are as disgusting as the sea cucumber. There are plenty of weird defense mechanisms in the animal kingdom, but the sea cucumber’s evisceration is the grossest of all. When threatened, they can eject parts of their internal organs to escape from a predator. Incredibly, it can regrow all of these in a matter of days, no harm done, ready to begin the process anew. Long story short, don’t pick up a sea cucumber or it might poop its guts out all over you.

#3: Boa Constrictors Can Feel Your Heartbeat

While some snakes kill with venom, for others their preferred murder technique is constriction. Luckily, any kind of constrictor eating a human is rare, but if one did decide to attack, you wouldn’t be able to escape by playing dead. This is because the snakes have evolved the incredible ability to detect the heartbeat of whatever they’re crushing. They do this because they don’t actually kill you by suffocating you. They squeeze so tightly that your blood flow is cut off; as soon as you fall unconscious, cardiac arrest will finish the job.

#2: Constipated Scorpions

While some creatures can shed their tails to escape predators without ill effects, the same isn’t true for scorpions. When their tail is caught in something, some South American scorpions can let it snap off, living on to fight another day. But the trade-off is brutal - because the scorpion’s anus breaks off with the tail. A slow and agonizing death follows, as the scorpion continues to eat but is unable to relieve itself. The pressure builds up increasingly, and this will keep happening for up to eight months until its inevitable death.

Before we unveil our top pick, here are a few Honorable Mentions:

Deer Eat Bones
They’ve Been Seen Scavenging Human & Animal Remains For Vital Nutrients

Armadillos Carry Leprosy
You Could Contract This Ancient Disease by Touching an Infected Animal

Eggs Made of Blood
Female Mosquitoes Use the Protein in the Blood They Drink to Grow Their Eggs

Pigs Will Eat Anything
Hungry Pigs Have Even Been Known to Eat Human Beings

Giant Jellyfish Sink Ships
Ships Have Capsized Trying to Pull Aboard Enormous Nomura’s Jellyfish

#1: Cockroaches Are Nearly Invincible

Perhaps the sturdiest creatures in the world, the humble cockroach is a common pest you’ll struggle to get rid of. Because they live for about a year and breed so quickly, they develop genetic resistances to the pesticides and chemicals we use to flush them out. But even decapitation won’t get rid of a roach. This is because they don’t need their brains to control their breathing, and rather than breathing through their mouth, they breathe through tiny holes in their bodies. If you chop the head off a roach, not only will the body continue to move, but so will the head; it can keep going for up to a week.