In
biology, a
nymph is the immature form of some
invertebrates, particularly
insects, which undergoes gradual
metamorphosis (
hemimetabolism) before reaching its adult stage. Unlike a typical
larva, a nymph's overall form already resembles that of the adult. In addition, while a nymph
moults it never enters a
pupal stage. Instead, the final moult results in an adult insect. Nymphs undergo multiple stages of development called
instars.