Paguroidea

Hermit Crabs are social creatures that often live in large colonies, interacting through tapping, pushing, and shell-exchanging behaviors. They are opportunistic scavengers, feeding on algae, decaying organisms, and leftover food found along shorelines or in tide pools. Many species are active at night, using their strong sense of smell to locate food.

Most Hermit Crabs reproduce in the ocean, where females release eggs that hatch into planktonic larvae. These larvae go through several stages before settling on the seafloor and eventually seeking their first shell. Land hermit crabs (such as Coenobita species) must return to the sea to release their eggs, despite living on land as adults.

Hermit Crabs have hard front claws and legs but soft, curled abdomens that require the protection of a borrowed shell. They may exchange shells by forming “vacancy chains,” where multiple crabs line up from largest to smallest to swap shells in sequence. Their coloration and size vary dramatically across species, from tiny intertidal crabs to large terrestrial forms like the coconut crab’s relatives.

Hermit Crabs are found in oceans, coastal areas, and tropical islands worldwide. Their reliance on discarded snail shells links their evolutionary success to the availability of gastropod habitats and healthy marine ecosystems.

Hermit Crab populations are generally stable, though some species face threats from habitat loss, pollution, and declining availability of natural shells due to overharvesting and environmental decline. Conservation efforts increasingly focus on coastal protection and reducing plastic waste, as crabs sometimes mistakenly use plastic debris as shells.