 Molting, in biology, molting British English or molting American English also known as slying, shedding, or in many invertebrates, ecstasies, is the manner in which an animal routinely casts off a part of its body often, but not always, an outer layer or covering either at specific times of the year or at specific points in its life cycle. Molting can involve shedding the epidermis skin, pellage hair, feathers, fur, wool or other external layer. In some groups, other body parts may be shed, for example, wings in some insects or the entire exoskeleton in arthropods.