Flea is the common name for any of the small wingless insects of the order Siphonaptera. Fleas are external parasites, living by hematophagy off the blood of mammals and birds, which are also flightless. In the past, however, it was most commonly supposed that fleas had evolved from the flies, based on similarities of the larvae.
Fleas Life Cycle
Fleas pass through a complete life cycle consisting of egg, larva, pupa and adult. Completion of the life cycle from egg to adult varies from two weeks to eight months depending on the temperature, humidity, food, and species. Normally after a blood meal, the female flea lays about 15 to 20 eggs per day – up to 600 in its lifetime – usually on the host (dogs, cats, rats, rabbits, mice, squirrels, chipmunks, raccoons, opossums, foxes, chickens, humans, etc.).
Eggs loosely laid in the hair coat drop out almost anywhere, especially where the host rests, sleeps or nests (rugs, carpets, upholstered furniture, cat or dog boxes, kennels, sand boxes, etc.). Eggs hatch between two days and two weeks into larvae found indoors in and along floor cracks, crevices, along baseboards, under rug edges and in furniture or beds. Outdoor development occurs in sandy gravel soils (moist sand boxes, dirt crawlspace under the house, under shrubs, etc.) where the host may rest or sleep. Sand and gravel are very suitable for larval development which is the reason fleas are erroneously called “sand fleas.”
Larvae are blind, avoid light, pass through three larval instars and take a week to several months to develop. Their food consists of digested blood from adult flea faeces, dead skin, hair, feathers, and other organic debris; larvae do not suck blood. Pupae mature to adulthood within a silken cocoon woven by the larva to which pet hair, carpet fibre, dust, grass cuttings, and other debris adheres. In about five to fourteen days, adult fleas emerge or may remain resting in the cocoon until the detection of vibration (pet and people movement), pressure (host animal lying down on them), heat, noise, or carbon dioxide (meaning a potential blood source is near). Most fleas overwinter in the larval or pupal stage with survival and growth best during warm, moist winters and spring.
The “flea season” is traditionally, depending on the geographical region, from the beginning of summer and into the early autumn, but in warmer areas can last year round. Warmth and humidity are the ideal conditions!