Which metamorphosis type is exhibited by fleas?

Fleas exhibit complete metamorphosis, which is characterized by four distinct life stages: egg, larva, pupa, and adult. This type of metamorphosis is notable for the significant transformation that occurs between the larval and adult stages.

In the egg stage, fleas are laid in the environment, often in places where hosts live. Once the eggs hatch, the larva emerges, resembling small, worm-like creatures that undergo several molts. These larvae are quite different from the adult fleas—they do not have the same body shape, lack wings, and are not yet capable of jumping or feeding on blood.

The larva then enters the pupal stage, where it undergoes further transformation in a protective casing. The pupal stage is a time of significant internal change, leading to the adult flea, which emerges ready to seek a host to feed on blood. This complete transformation across all life stages distinguishes complete metamorphosis from other types of metamorphosis, such as simple or gradual. Simple metamorphosis typically involves just three stages (egg, nymph, adult) and does not include a pupal stage, while gradual metamorphosis is characterized by more subtle changes without a clear pupal phase, focusing instead on