Land hermit crabs are crustaceans known as Coenobita clypeatus. They live in the wild in the western Atlantic. Hermit crabs have a three sections: a head, a body (cephalothorax), and an abdomen which they protect with their shells. Hermit crabs have gills on their big claw in order to conserve moisture. Hermit crabs sometimes go for long periods of time without food or water. However, hermit crabs need to keep their gills wet to maintain good health. It is usually best to place them in or near water once a day. Although hermit crabs might look harmless, they can use their claws to grip things tightly. Trust me; I've had one attached to me for five minutes. If one should attach themselves to you, put them under luke warm water. Even the very smallest hermit crabs can draw blood if it becomes frightened. Hermit crabs usually travel in groups of 25 (approx.) in the wild. So it is important when you have hermit crabs as pets that you have several of them to keep each other company.