Every ocean of the world has crabs in it. Some crabs live in shallow waters, close to land, and others live in deep waters. But not all crabs live in the ocean, some of them live on land.All crabs have legs, their front legs are large, with strong claws on the end. Tese are called pincers. The pincers are used for catching and killing small animals. They are also used for digging and fighting. A crab is covered with a hard shell. This keeps it safe from its eneies.