Hermit crabs are often sold as disposable novelty pets, but they are complex social animals with welfare needs that include shell availability, social grouping, and appropriate humidity for respiratory function.
Hermit crab welfare in captivity is profoundly misunderstood due to their marketing as low-maintenance starter pets. Sold in small plastic containers without adequate humidity, heat, or companions, hermit crabs die slowly from respiratory failure and dehydration. Without a range of appropriate shells, crabs cannot moult successfully - a traumatic and potentially fatal process in inadequate conditions. Isolation from other hermit crabs deprives them of natural social behaviour. Painted shells block pore openings and cause toxicity. Good hermit crab welfare requires large, humid enclosures with deep sand for burrowing, a shell selection, access to salt and fresh water, and the company of other hermit crabs.