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.
