In a subway station in the Chinese city of Nanjing, vending machines sell live crabs. The crabs are kept at 0-10° C (32-50° F) – not enough to freeze them, but cold enough to make them docile. Around 200 crabs are sold daily – and if you buy a dead one, you’ll get three live ones for free.
A group of coconut crabs is called a “nightmare,” with leg spans reaching up to three feet, and are known to climb trees on their native islands in the Pacific and Indian oceans; they’ve also been observed devouring chickens and kittens.
Hermit crabs form gangs to steal other hermit crabs’ shells.
There is a species of crabs that can grow larger than humans.