They can’t fly, but they can sure jump. Fleas are among the best jumpers of all living creatures. They can jump 200 times their body length. Widespread pests of people and pets, fleas are wingless, tiny insects that can seem to be everywhere. Mature fleas live on blood from the much larger creatures they ride around on. Many kinds of fleas jump around. Each kind of flea being quite versatile and adaptable.
The worst misdeed perpetrated upon mankind by this kind of bug involves the kinds of fleas which ride on rats and carry the bacteria that cause bubonic plague. Such fleas have changed the course of history.
Fleas are tiny, 1/16 to 1/8 inch in length. They are laterally compressed, that is, thin from side-to-side, permitting easy movement through the hairs and feathers of their hosts. Their mouth parts are especially adapted to permit feeding on the blood of their hosts.
The Flea Life Cycle
In order to lay eggs, a female flea must first eat blood. Dog blood or cat blood will do and the flea doesn’t care about the bloodline. The well-fed female will lay up to 20 eggs at a time, often deposited on the host, but easily rolled off onto the ground or carpet where the host animal might lie down to rest. Such eggs take two days to two weeks to hatch. The larvae which emerge from the eggs will probe around for nourishment which can be almost any organic material.
After three larval stages the individual will spin a cocoon of silken fiber and go into a pupal state. These pupae may stay for some length of time or they may emerge in a week. Whenever they emerge it is as a mature flea, looking for blood. Actually fleas appear to have good eyesight which they use to navigate from one part of their host to another.
On the other hand, the silk-enclosed pupa might just sit there from year to year, maybe not forever, but for some extended time, awaiting the right conditions to emerge. Thus you might think you have eliminated fleas only to have them come back with a vengeance in some future season.
Ideal Conditions for Fleas
Fleas live on a variety of warm-blooded hosts including mice, rats, ferrets, squirrels, rabbits, chickens, and of course cats, dogs, and humans. All of these can itch because of the action of the fleas they carry. The host will scratch, bite, or peck in the vicinity where the flea is feeding. Not that the scratching does much good. Fleas are parasites which appear to do no good for the animals on which they ride and jump.
Fleas have some allies, however. Tapeworms appear to depend on fleas to carry their eggs into the guts of certain animals. What a comforting thought.
Flea larvae are sensitive to humidity, meaning that there must be some water associated with the organic material they find to eat. Of course, a flea egg can wait out a long dry spell.