7 Spooktacular Animal Facts for Halloween

WARNING: The following animal facts are extremely creepy and may induce chills, thrills, and an urgent desire to visit the Zoo in whoever reads them. Please proceed at your own risk. 

The alligator snapping turtle hunts by using its thin, worm-like tongue as a lure to bait prey. Unsuspecting fish and amphibians swim towards the tongue expecting an easy meal... and then SNAP! Dinner is served.  

As California sea lions age, their teeth gradually turn black. Fortunately, the dark color isn’t from cavities or rot—it’s caused by a healthy coating of bacteria that protects their teeth. (Always helpful when your dinner has tentacles.) 

Some bird species, like the brown-headed cowbird, are brood parasites—they sneak into other birds’ nests and lay their own eggs. The unsuspecting bird parents will lovingly tend to the (often much larger and hungrier) young cowbirds while their own offspring fail to thrive.

The gray catbird relies on a simple method for thwarting brood parasites. If they spot an unrecognized egg in its nest, they’ll punch a hole in the shell with their beak and then shove the egg from the nest. Brutal, but effective.

What’s scarier than being stalked on an island by a deadly predator? How about sixty razor-sharp teeth and side helping of venom? 

The bite of a Komodo dragon contains a hemotoxic venom that prevents blood from clotting, keeping even minor wounds bleeding for as long as possible. If their prey escapes an initial attack, this lizard will use its sense of smell to track the wounded animal for days until it collapses. Persistence pays off. 

Lose a limb? Slice off a toe? Misplace part of your brain? No problem. 

After sustaining an injury, some amphibians, like the Eastern newt, can fully regenerate missing limbs, hearts, spinal cords…and even portions of their brains. 

Loggerhead shrikes are part of a bloodthirsty family of “butcher birds” known for their gruesome hunting tactics: they use their sharp beaks and muscular necks to snap the necks of their prey. Then, they impale the bodies on sharp thorns or barbed wire, feasting on the remains later. Vlad would be proud. 

Caecilians—a family of more than 200 species of limbless, worm-like amphibians—are already strange.  

But certain live-bearing caecilians have a truly bizarre method of parenting. Developing babies use their rasp-like teeth to scrape the walls of their mothers' oviduct—the amphibian equivalent of a uterus—and drink the nutrient-filled fluid that oozes out.

It gets gnarlier. In some egg-laying caecilians, babies peel off and eat fatty chunks of their mother’s skin, and even lap up a “milk-like” fluid she secretes to keep them fed.

As gruesome as it sounds, it's part of an effective parenting strategy: eating chunks of mom provides the babies with nutrients necessary for growth. How far would you go to feed your own kids? 

What do these eerie abilities have in common (other than they’re all from animals cared for at the Smithsonian’s National Zoo and Conservation Biology Institute)? Each behavioral adaptation is a strange—and sometimes unsettling— survival strategy found in the animals’ wild counterparts. They may seem macabre to us, but they highlight the incredible diversity of life on our planet, which often thrives in unexpected ways.

Plan your visit to the Zoo this Halloween (or anytime) to see what other creatures you’ll encounter while learning how Smithsonian scientists are working to protect them for generations to come... before it's too late.