Fleas can live on animals and in homes, yards, parks and so on. They thrive outdoors in warm, moist environments and are most evident from April through November. Pets and anyone entering your home can bring in fleas and because of their mobility, there is no place they cannot go. Only about 10% of the flea population, mostly adults, live on animals once inside the home. The remaining 90% of the flea population including eggs, larvae, pupae and some adults reside in bedding, furniture, carpeting and cracks or crevices in flooring.
An adult female flea can lay up to fifty eggs a day after obtaining a host blood meal. These eggs are white, roundish and non sticky. They often fall immediately upon being laid and do not remain on animals. Flea eggs can take approximately two to twelve days to hatch into larvae.
When flea larvae break through their eggs, they are semi-transparent white in color and have no eyes or legs. These maggot-like larvae do not feed from hosts directly, but instead they feed on the feces, also known as dried blood or flea dirt, discharged by adult fleas. They also eat various types of organic debris such as dead insects and food particles. After about four to eighteen days, larvae spin silken cocoons and begin pupating.
Larvae remain as pupae in their cocoons for a period of as little as three days to as long as a year. Stimuli such as vibrations, rising levels of carbon dioxide or warm temperatures can speed up this stage of the life cycle process providing for sooner development.
Within the first 24-48 hours of emerging from their cocoons, adult fleas will seek a host for their first blood meal. Female fleas cannot lay eggs until they obtain a blood meal. Shortly after feeding, adult fleas will mate and the females will begin laying eggs within two days, thus beginning the life cycle all over again.
Fleas can be a health hazard to both pets and people. The bites they inflict on humans may appear in clusters of three or four small bumps with a red "halo" around the bite center. These bites can trigger allergic reactions such as severe itching, skin irritation and redness. Fleas can also transmit other serious diseases to animals and individuals alike including bartonellosis, plague, tapeworm and typhus.