Hermit crabs are the group of crabs which are well-known for using empty sea-snail shells as a ‘home’. They do not grow a fully protective shell of their own, instead using discarded seashells to provide them with protection. As an individual hermit crab grows older, it also grows larger, and will eventually become too big to fit in its seashell home. This means that it must find and move into a larger shell. There is usually fierce competition for empty shells with several hermit crabs fighting for the ‘moving in rights’. Hermit crabs have one pincer larger than the other and this depends upon the species. Common hermit crabs are right-handed with the larger claw on the right hand which is used as a door to shut the crab in the shell when danger is present!
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