hermit crab inside the shell of a whelk
A hermit crab is an animal that uses the abandoned shell of other animals.Here is a quote from Wikipedia:
Most frequently, hermit crabs use the shells of sea snails (although the shells of bivalves and scaphopods and even hollow pieces of wood and stone are used by some species).
A whelk is a type of sea snail, in the most general sense of the term, snail.
I remember my first experiences with hermit crabs as a child on vacation with my family on and near the beaches of Montego Bay. Such creatures (hermit crabs) were unheard of in the San Francisco Bay area…