Crayfish, or crawdads, are crustaceans that live in freshwater environments throughout the world, except for India and Antarctica. These animals have five pairs of legs, or 10 legs total—hence the Latin name for the crayfish order, known as Decapoda (“10-footed”). The front two legs are modified into large claws, called chelae, used for defending themselves and snagging food.
There are nearly 600 known species of these creatures, with new varieties found every year. The southeastern United States and, to a lesser extent, Australia, are considered crayfish diversity hot spots.
They eat just about anything they can get those chelae on, including insects, algae, fish, invertebrates, carrion, and plant detritus.