Cool claws
These animals have two pairs of walking legs and one smaller pair of legs that holds them in their shells. They also have two claws; one much larger than the other. The crab uses the bigger claw for defense and for shredding food. It uses the smaller claw for eating. If it loses one of its legs or claws, it can grow a new one.
My place or yours?
As a
hermit crab
grows, it needs bigger shells. Like any picky homeowner, it checks out its options carefully, even climbing inside empty shells to try them on for size. Sometimes a large crab steals the shell of a smaller crab, throwing out the owner, who has to make do with the discarded shell of the larger crab.