Hermit crabs use a sea snail shell to protect their soft rear body from predators, curling the rear body and hooked tail
around the inside of the shell to walk about. They move to a larger shell as they grow.
The (Dwarf) Blue-leg/Blue-legged Hermit Crab, also called the Tri-coloured and Three-coloured, is native to the Caribbean.
As its name indicates, it has blue legs, with red banding and white tips. It is about 4cm (1.5 inches) long. Both claws are equal in size.
Moving to a larger shell is a dangerous time. The crab is a scavenger eating dead and decaying matter, algae and detritus.