Infestation populations can and are often found to be extreme even when the host is not available. Fleas are small wingless insects averaging two to four millimeters. The body is compressed latterly to permit unobstructed movement between hairs and feathers. Adult fleas have piercing-sucking mouth parts. As adults, they can jump eight inches vertically and 16 inches horizontally.
Fleas have a metamorphosis.
Egg, larva, pupa, and adults can usually all be found during the infestation. The adult flea lays her eggs on the host or in the bedding or rest areas of the host. The several hundred eggs laid by the female flea will hatch within several weeks or as soon as two days. The larva stage usually appears crawling worm-like in the 'salt and pepper' litter, associated with heavy flea populations. The larva feeds on detritus including blood rich feces from the adult fleas.