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
Rufous-breasted hermit Rufous-breasted hermit The rufous-breasted hermit or hairy hermit ("Glaucis hirsutus") is a hummingbird that breeds from Panama south to Bolivia, and on Trinidad, Tobago and Grenada. It is a widespread and generally common species, though local populations may change in numbers and disappear altogether in marginal habitat It is long and weighs on average. The bill measures around and is strongly decurved, long and thin – though compared to the bills of other hummingbirds, it is rather robust. The rufous-breasted hermit has a brownish head, bronze-green upperparts and rufous underparts. The tail has green central feathers and rufous outer feathers,