Metamorphosis is a biological process by which an animal physically develops after birth or hatching. It involves a conspicuous and relatively abrupt change in the animal's body structure through cell growth and differentiation. Some animals undergo complete metamorphosis, while others undergo incomplete metamorphosis.
Complete metamorphosis involves four distinct stages: egg, larva, pupa, and adult. The larva looks very different from the adult and typically lives in a different environment and has different food requirements. When the larva is ready to transform into an adult, it enters the pupa stage. Inside the pupa, the larva's body undergoes a dramatic reorganization and emerges as a fully formed adult.
Incomplete metamorphosis involves three stages: egg, nymph, and adult. The nymph looks similar to the adult but is smaller and lacks fully developed wings. As the nymph grows, it sheds its outer skeleton several times. With each molt, the nymph becomes larger and more similar to the adult. When the nymph is fully grown, it undergoes a final molt and emerges as an adult.
Examples of animals that undergo complete metamorphosis include butterflies, moths, beetles, and flies. Examples of animals that undergo incomplete metamorphosis include grasshoppers, crickets, cockroaches, and dragonflies.