Some organisms, like some fast plants, are born , mature, and die rapidly. Other organisms, like bristlecone pine trees, have life cycles lasting for thousands of years. Another organism with a rapid life cycle is the fruit fly . However, the fruit fly's life cycle involves a process of metamorphosis . During its life cycle, the fruit fly changes from one form to a completely different form.
Butterflies are also well-known for their metamorphosis.
During the fruit fly's life cycle, it changes from egg to larva to pupa to adult. Each of the four distinct life phases is a natural part of the life cycle. The egg soon hatches into a larva which is an immature animal. The larva of the fruit fly looks completely different than the adult. Soon, the larva enters into the pupa stage by covering itself with a protective case known as a cocoon .