Subclass of the insects including the orders with a complete metamorphosis. In these insects the external (and internal) changes during the life history are the greatest. The eggs hatch into larvae which feed actively during the different instars. The larvae may or may not have legs. The development of wings is not visible during the larval stages. After several molts a pupa is formed. A pupa is an inactive stage, it does not feed and it does not move. Sometimes the pupa is protected by a cocoon of silk, or it is found in an earthen cell in the soil. During this pupal stage big changes take place internally. After the pupal stage, a highly active winged adult appears. Often, the larvae and the adults live in different types of habitat and use different types of food.