Hermit Crabs Move House
1A hermit crab is a small animal with hard claws and legs. The back part of its body is soft and curled. This soft part needs protection, but a hermit crab does not grow its own shell. Instead, it usually lives in an empty shell that once belonged to a sea snail.
2The crab tucks its soft body inside the shell and holds on tight. When danger comes near, the crab pulls back inside. Its biggest claw can block the opening like a door.
3A hermit crab keeps growing, but its shell does not. After a while, the shell feels too tight. Then the crab goes looking for a bigger home. It feels inside each empty shell with its claws to check the size. When it finds a shell that fits, it moves in.
4Sometimes, a group of crabs gathers near one large empty shell. The crabs may line up by size. The biggest crab moves into the new shell first. Then the next crab moves into the shell that the biggest crab left behind. In the end, many of the crabs have homes that fit better.
5Some kinds of hermit crabs live on land near the beach. Many other kinds live in the ocean. Wherever they live, hermit crabs need shells that fit them.