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
Bolas spider Bolas spider A bolas spider is any of several species of orb-weaver spider that, instead of spinning the typical web, hunt by using a sticky 'capture blob' of silk on the end of a line, known as a 'bolas'. By swinging the bolas at flying male moths or moth flies nearby, the spider may snag its prey rather like a fisherman snagging a fish on a hook. Because of this, they are also called angling or fishing spiders (although the remotely related genus "Dolomedes" is also called a fishing spider). The prey is lured to the spider by the production