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,
Tapajós hermit little hermit, and the Tapajós hermit was believed to be most closely related to the black-throated hermit. In 1996 it was suggested that the Tapajós hermit was entirely invalid, and actually represented hybrids between the reddish and streak-throated hermits. In 2009 this hypothesis was shown to be incorrect, and the Tapajós hermit was instated as a valid species. Tapajós hermit The Tapajós hermit ("Phaethornis aethopygus") is a species of hummingbird in the family Trochilidae. It is found in the south-eastern Amazon in Brazil, and its common name refers to the Tapajós River, which forms the western border of its distribution.