It does not build its own home. It steals one. The Hermit Crab relies on the discarded shells of sea snails for protection. Its abdomen is soft and vulnerable. Without a shell it is prey. With a shell it is secure. It drags its borrowed house across the sand. It retreats into it at the slightest disturbance. This is not laziness. It is survival. The species inhabits rock pools and shallow coastal waters. It favours areas where gastropod shells are abundant. Empty turban shells and periwinkle shells are preferred. As the crab grows it must find larger accommodation. This leads to competition. Crabs will fight over prime real estate. The larger crab usually wins. The loser is left exposed. Range covers both main islands. It is found in harbours, estuaries and open coastlines. It tolerates a wide range of salinities. This adaptability helps it thrive in changing environments. It is often seen by beachcombers turning over rocks. It scuttles away quickly. It does not like attention. Diet consists of detritus, algae and small dead animals. It is a scavenger. It cleans up the seabed. It eats what others leave behind. This role is unglamorous but essential. Without scavengers the shore would be cluttered with decay. The hermit crab keeps things tidy. In its own way. Threats include habitat loss and pollution. Plastic debris can be mistaken for shells. A crab that adopts a plastic cap may die. It cannot grow. It cannot breathe properly. Human activity also removes shells from beaches. Collectors take them as souvenirs. This leaves fewer homes for the crabs. The impact is subtle but significant. Life span is two to three years. Growth is slow. Moulting occurs regularly. Each moult requires a new shell if the old one is too tight. The cycle is continuous. Find shell. Grow. Find bigger shell. Repeat. It is a life of constant relocation. And it seems to work.