Nymphs are one of the life stages of some types of insects. A gradual metamorphosis proceeds from egg to nymph to adult. Within the nymph stage the insect grows and molts (sheds the outer skin), grows and molts, for a varying number of times. These stages within the nymph stage are called instars. Essentially all the weight gain of the insect takes place during the nymph instars.

Nymphs look like small adults except they are without wings and may be a different color. They also occupy the same niche in nature as their adults progenitors.

An example of an insects that has a nymph stage that we have probably all observed is the grasshopper.

To constrast, other insects undergo a complete metamorphosis that proceeds from egg to larva to pupa to adult. An example of this type of insect is a butterfly. Each stage looks very different and occupies a different niche in nature than the adult or other stages.