Fleas are a nusciance for pet owners and among the most common parasites found on dogs and cats . Most prefer non-human hosts, but many can and do feed on humans when infestations are heavy or when there is a lack of other preferred hosts.
Fleas are small, wingless insects, averaging 1/12 to 1/6 inch long. Their powerful legs permit them to jump as much as 7-8 inches vertically and 14-16 inches horizontally. Fleas go through a complete metamorphosis. The smooth, rounded, light-colored eggs tiny and can barely be seen. Eggs are usually laid on the host, but they can also be laid by adults who have fallen to the ground, carpet, or bedding. Due to this, areas where the host rests and sleeps become one of the primary habitats of developing fleas and their eggs. A female flea will produce a few eggs each day and can lay up to 5000 or more over the course of her life. Depending on the environment, these eggs will hatch in anywhere from 2 days to several weeks, but most will hatch within 7-14 days.
Adult fleas feed on blood while the larvae eat a diet consisting of dried blood. Flea bites caused by this feeding can become inflamed and cause allergic reactions. After feeding, the flea will begin mating and start the life cycle all over again. Once the flea larvae emerge from the eggs they feed on any available organic material they can find such as feces, dried insects, and vegetable matter. Being blind, they prefer to avoid sunlight, keeping to dark places like sand, cracks and crevices, and bedding. Given adequate supply of food, larvae will pupate and weave a silken cocoon within 1-2 weeks after 3 larval stages or instars. Within about two weeks the adult flea is fully developed and ready to emerge from the cocoon. They may, however, overwinter in the larval or pupal stages awaiting the presence of a host nearby.
Flea populations consist of approximately 50% eggs, 35% larvae, 10% pupae, and 5% adults. The life cycle of the flea can be as short as one year but can be several years in ideal conditions.