Word: Molting
Definition:
Molting is the process where certain animals, like arthropods (insects, spiders, and crustaceans) and reptiles (like snakes and lizards), shed their old skin or outer layer to allow for growth or to get rid of parasites.
In scientific contexts, you might hear about "ecdysis," which is a specific term for the molting process in arthropods. You might also encounter "exuviation," which refers to the shedding of the outer layer.
There aren’t specific idioms or phrasal verbs directly related to "molting," but you might hear phrases like "turning over a new leaf," which can metaphorically relate to shedding the old in favor of the new.
Molting is an important process for many animals, helping them to grow and stay healthy.