Adults are parasites that draw blood from a host. Larvae feed on organic debris, particularly the feces of adult fleas, which contain undigested blood. Fleas commonly prefer to feed on hairy animals such as dogs, cats, rabbits, squirrels, rats, mice and other domesticated or wild animals. Fleas do not have wings, although they are capable of jumping long distances.
Eggs are not attached to the host. Eggs will hatch on the ground, in rugs, carpet, bedding, upholstery or cracks in the floor. Most hatch within two days.
Since fleas are relatively easy to see in their adult stage, most of the attention is directed at adult fleas. Adult fleas are usually easy to locate, especially if the homeowner and their pets return to the house after a long vacation or other absence during which the resident flea adults were not able to take a blood meal. Upon returning, the homeowners are often greeted by fleas jumping around and trying to land on them and their pets.
The flea eggs, larvae and pupae are another situation. Since these stages are much more secretive and much less active, they are found in out-of-the-way places like behind, under or in the furniture; in the pet’s bedding; inside cracks and grooves in the floors; and in the carpets. Flea eggs that were deposited by the female adult, fall off your pets as they move, allowing them to be disbursed throughout the environment where a pet spends time. Flea eggs represent about one-half of the entire flea population present in an average home. Larvae make up about 35 percent of the flea population.
If conditions are favorable, the larvae will spin cocoons in about 5-20 days after hatching from their eggs. The cocoons are the flea’s pupal stage and account for about 10 percent of the flea population. This cocoon stage is the last developmental stage before the adult flea emerges. If environmental conditions are not right for emergence, the cocoon can protect the developing flea adult for months or even longer. The adult flea does not emerge until a potential host is detected by vibration, rising levels of carbon dioxide and body heat associated with the host. A pet walking by, or people moving in the house alert the flea to emerge from its cocoon to feed. Once a flea has emerged from the cocoon, it will begin taking a blood meal on a host within 24-48 hours. Shortly after the first meal, adult fleas will mate and the female fleas begin laying eggs on her host within a few days. Female fleas are not able to lay eggs until they obtain a blood meal.
Many signs can indicate flea activity. A common indication would be pets that repeatedly scratch and groom themselves. This is caused by the discomfort of the flea activity as the adult fleas feed on the pet’s blood. People also may experience bites which leave behind itchy bite marks (a medical doctor can be consulted, since there are other sources of skin irritation beside fleas). Flea dirt, the adult flea feces, also can indicate activity. Flea dirt looks similar to coarse ground black pepper and may be seen in pet beds, carpets, rugs and other areas where the animal host rests. Read more on flea infestations.
Fleas are not usually found infesting a homeowner’s beds and bedding. Fleas that are observed in beds and bedding are most likely there only to take a blood meal or were perhaps dislodged from the animal if the pet is allowed to sleep in the same bed as the homeowner. However, if the homeowner does not wash and change the bedding for a long while, it is possible that the immature stages of the fleas could possibly take up residence in a bed or bedding. The more likely situation is that flea eggs, larvae and pupae are living under the bed or, even more likely, are living in the bed and bedding of the household pet(s).