Crustaceans are a group of animals whose skeletons are on the outside of their bodies. They live in saltwater and breathe through gills, just like fish. They have many pairs of legs, and their bodies are jointed, like a human’s elbows or knees. Crustaceans use feelers for touching, feeling and smelling. Crabs, shrimp, lobsters and barnacles are all crustaceans. Some crustaceans can swim, like crabs and shrimp. Some can only scuttle along the ocean floor, like the lobster. And the barnacle sticks to a hard spot and never moves at all.

The hermit crab is also a crustacean, but he does not grow his own shell. He has to find empty shells of other animals to move into when he gets too big for his shell.