The shell is one of, if not the most, important part of your crab's environment. Your crab must have a shell to maintain moisture, be protected, and live a normal life.

Hermit crabs have exoskeletons on the front half of their bodies. The back half is delicate and exposed. For this reason, hermit crabs must have some other form of protection. They obtain this by occupying the vacant shells of snails and other animals. The shell protects the back part of the crab from harm.

Always keep extra shells in your crab tank. If your crab outgrows his current shell, he'll need to move out and into another one. These shells need to be bigger than the shell he is currently residing in.

Studies show crabs prefer darker shells from lighter colored ones. Nobody is really quite sure why this is. I have personal experience with this, as I own two crabs who have long ago outgrown their very black shells but refuse to move into the browner colored ones in their tank.

If you live near a beach and wish to collect your shells there, disinfect them to kill any harmful bacteria that might get introduced into your hermit home. To do this very easily, boil them in water for about 10 or 15 minutes. This not only loosens any stubborn dirt, but also insures all bacteria are killed off.

This hermit crab has decided to change shells. After developing from a larval stage to the adult stage, the adult crab will spend the rest of it's life looking for comfortable shells to call home. Once the crab has decided on a shell, he will inspect it in every way possible. He checks the shape and opening with his antennae and sticks his claw into the shell to check for shapes and sizes. If the shell passes all the crab's criteria, he may decided to take the shell for a test drive. Very quickly he leaves his old shell and slips his abdomen into the new one, keeping a tight hold on the old one with his legs or claws. If he likes it, he scurries on his way with the new shell. If not, he slides back into the old one and searches more. This is all done very quickly, since the crab is vulnerable to predators while changing shells.