Hermit crab wood and stone are used by some species). The tip of the hermit crab's abdomen is adapted to clasp strongly onto the columella of the snail shell. Most hermit crabs are nocturnal. Hermit crabs can be divided into two groups: As hermit crabs grow, they require larger shells. Since suitable intact gastropod shells are sometimes a limited resource, vigorous competition often occurs among hermit crabs for shells. The availability of empty shells at any given place depends on the relative abundance of gastropods and hermit crabs, matched for size. An equally important issue is the population of organisms that prey
Little hermit and some small insects. It feeds mainly by trap-lining. Little hermit The little hermit ("Phaethornis longuemareus") is a hummingbird that is a resident breeder in north-eastern Venezuela, northern Guyana, Suriname, French Guiana and Trinidad. This lowland species occurs in various semi-open wooded habitats, e.g. mangrove, secondary forest, plantations and scrub. In Trinidad it also occurs in rainforest. It is fairly common in most of its range, and therefore listed as Least Concern by BirdLife International. Previously, several other small hermits were considered subspecies of this species. This includes the stripe-throated hermit ("P. striigularis") of Central America and north-western South America,