Female cat fleas, Ctenocephalides felis, have the same basic life cycle as all fleas. An egg stage, a 3 level instar larval stage, pupae stage, and finally adulthood is the life cycle every species of flea undergo. However, unlike most flea species, cat fleas lay their eggs directly on a living host which is typically a dog or cat. Cat fleas can not reproduce on humans.
Female cat fleas are capable of laying 20-30 eggs on a suitable host in one day. Each egg is 19/32 of an inch in length which is visible to the human eye. The eggs are transparent when first laid by the female. They gradually darken to a solid white color. When first deposited on the host, the egg is slightly damp which prevents them from dropping off. Within two hours, the eggs have dried and 60% of them have fallen off into the environment. Host activity, grooming, and coat length also play a factor in when the egg is dislodged.
Scientists have discovered that cat fleas deposit fewer eggs at dawn and dusk. Typically, the eggs drop into the environment where pets sleep. Although the eggs will generally hatch within two days, temperature and humidity do influence the larvae emergence time.
Age of the adult female also influences egg production. Younger females produce fewer viable eggs then older females. Scientists have discovered that adult female cat fleas reach peak egg production anywhere from 3-9 days after emergence from the pupae. Females must also take a blood meal from their hosts in order to have successful mating.
When dealing with a flea infestation, it is important for the homeowner to treat all stages of the flea life cycle. Flea products containing an insect growth inhibitor are necessary in order to eliminate the egg stage of the cat flea. Eggs generally fall into carpeting, grass, and bedding making them very difficult to see. Vacuuming and washing any pet bedding is an important step in eliminating a flea problem.