In biology, exuviae are the remains of an exoskeleton and related structures that are left after ecdysozoans (including insects, crustaceans and arachnids) have molted.
As studying insects, crustaceans, or arachnids directly is not always possible, and because exuviae can be collected fairly easily, they can play an important part in helping to determine some general aspects of a species' overall life cycle such as distribution, sex ratio, production, and proof of breeding in a habitat.
[2] The Latin word exuviae,[3] meaning "things stripped from a body", is found only in the plural.
[4] Exuvia is a derived singular form, although this is a neologism, and not attested in texts by Roman authors.
Only a single historical work by Propertius uses the singular form exuvium, but in the meaning "spoils, booty".