The hermit crab has a hard, calcified pre-body and a soft, bag-shaped rear body which it places in an empty snail house. The hermit crab is reddish yellow, and it has strong and uneven claws at the front of the body. As the crayfish grows, it needs to change the house with a larger one, and often the abandoned house is taken over by a smaller crayfish. Many snail housings fit the snail at first, but in the end it is only houses from the whelk that can hold a large hermit crab. However, if a whelk is covered by a brown crust, it has most likely been home to a hermit crab. The brown is the remnants of small polyps, that the snail removes while it is alive, whereas the hermit crab lets them remain as they camouflage and protect the house.
Did you know that:
Hermit crabs are scavengers living on dead animals and parts of plants.