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,
Spider wasp Spider wasp Wasps in the family Pompilidae are commonly called spider wasps or pompilid wasps. The family is cosmopolitan, with some 5,000 species in six subfamilies. All species are solitary, and most capture and paralyze prey, though members of the subfamily Ceropalinae are cleptoparasites of other pompilids, or ectoparasitoids of living spiders. In South America, species may be referred to colloquially as or , though these names can be generally applied to any very large stinging wasps. Furthermore, in some parts of Venezuela and Colombia, it is called , or "horse killers", while in Brazil some particular bigger and brighter