Hermit crab gives rise to the popular name "hermit crab", by analogy to a hermit who lives alone. Several hermit crab species, both terrestrial and marine, have been observed forming a vacancy chain to exchange shells. When an individual crab finds a new empty shell it will leave its own shell and inspect the vacant shell for size. If the shell is found to be too large, the crab goes back to its own shell and then waits by the vacant shell for up to 8 hours. As new crabs arrive they also inspect the shell and, if it is too big,
Saw-billed hermit to the typical hummingbirds, Trochilinae (Hinkelmann, 1999). This, coupled with the considerable number of autapomorphies such as the unusual bill, suggest it is the most primitive species of the hermit lineage; a situation paralleled by the equally unusual tooth-billed hummingbird in the Trochilinae. Saw-billed hermit The saw-billed hermit ("Ramphodon naevius") is a hummingbird from southeastern Brazil, the only member of the genus Ramphodon. It is around 14–16 cm long and is one of the heaviest of the hermits; its straight bill has a hooked tip. It lives in humid forests, where it aggressively defends feeding routes ("trap-lines") from individuals of