Lifestyles of the Small and Annoying
Flea eggs, about the size a grain of salt, are laid by the adult female in a pet's coat, but quickly fall off. Any area where the pet rests will have many eggs. Fleas remain in this stage for 3 to 12 days.
Eggs hatch into maggot-like larvae and usually live in dark areas deep in carpeting or lawns. They are less than one-fourth of an inch long. For 8 to 24 days (depending on the flea species and environmental conditions) the larvae feed on the blood-rich adult flea feces which fall off pets. However, under adverse conditions such as extremes in temperature or lack of food, fleas can prolong this stage for 6 months.
After the larvae stage, fleas spin a cocoon out of their own saliva and enter the pupal stage. They remain there for 5 to 15 days. When unfavorable conditions prevail (such as a lack of food) fleas can stay in the pupal cocoon for up to a year.
When stimulated by an increase in temperature, humidity, or carbon dioxide from a dog, cat or human, adults leave the cocoon. The adult fleas immediately look for a host, and, unless scratched off, will remain there.
The mouthparts of adults are adapted for puncturing animal skin and sucking blood, and they can consume
up to 15 times their body weight in blood a day.
When there is no available host, adult fleas can live for several months without feeding. Extremes in temperature or lack of food and water generally don't harm fleas.
Although they are only 1/25 of an inch long, adults can leap more than a foot to reach a host. (A four-foot tall child would have to jump further than the length of four football fields to equal the leaping power of a flea.)
The flea's body shape and the arrangement of hairs on its body - all pointing backward - make it very difficult for dogs and cats to dislodge them when scratching.
Once on a host, adults quickly begin to reproduce, thus starting the cycle all over. Fleas reproduce quickly. Female adult fleas can lay about 30 eggs per day, or up to a few hundred in a lifetime. The flea population can explode quickly.