Cannibalism is far from the ultimate taboo in nature, and animals have been eating their own kind for millions of years — the world’s oldest known case dating back to trilobites half a billion years ago.
Today, many creatures engage in this behavior. These cannibal animals don’t eat fellow members of their species all the time and some only become cannibalistic in specific, rare scenarios. But from hungry hippos to self-sacrificing spiders, here are 12 animals that eat their own.
Warning: This content could be unsettling to some readers.
Monkeys
Three white-faced capuchin monkeys (Cebus imitator) in a tree. (Image credit: Kenny Borenstein/Getty Images)
Monkeys engaging in cannibalism are usually associated with infanticide, or the killing of infants. For example, in 2019, researchers observed a group of Panamanian white-faced capuchin monkeys (Cebus imitator) cannibalizing a newborn in the Santa Rosa National Park in Costa Rica after the 10-day-old monkey fell from a tree.
Researchers who observed the cannibalism suspected that an adult male pushed or attacked the infant, causing its death. Adult males of many different species will kill unrelated offspring for the chance to sire their own.
Polar Bears
A polar bear (Ursus maritimus) covered in blood after catching a seal. (Image credit: Cavan Images/Raffi Maghdessian via Getty Images)
Most cases of polar bear (Ursus maritimus) cannibalism involve males killing cubs, sub-adults or — very occasionally — adult females. However, both male and female polar bears will scavenge on the carcasses of dead polar bears that have been killed and skinned by humans, according to a 2011 study published in the journal Arctic.
The Guardian reported in 2020 that cannibalism was on the rise in polar bears in northern Russia, possibly due to a lack of food, as melting sea ice driven by climate change and human activity force them away from their normal hunting grounds.
Jaguars
A jaguar (Panthera onca) in the Pantanal region of Brazil. (Image credit: Jami Tarris/Getty Images)
A 2010 study published in the journal The Southwestern Naturalist documented the first case of wild cannibalism among adult jaguars (Panthera onca). Two male jaguars appeared to have killed and partially eaten a female jaguar. The researchers believed that with plenty of prey in the area, the violent encounter likely stemmed from the social stress of unfamiliar jaguars meeting each other in the forest. Jaguar cannibalism can also occur during infanticide, although it’s rare.
Sand Tiger Sharks
Underwater photograph of a sand tiger shark (Carcharias taurus). (Image credit: Tomas Kotouc via Shutterstock )
Sand tiger sharks (Carcharias taurus) cannibalize each other before they’ve even left the womb.