Fleas

Fleas are tiny insects. Adults of most species vary from 1/16" to 1/8" in length. They are wingless and the bodies of adults are laterally flattened; in other words, they are much "taller" than they are "wide." Adult fleas have powerful legs with which they can jump extraordinary distances, considering their tiny size.

There are many varieties of fleas, with most being named after their preferred hosts. But the names are misleading. Most fleas will readily feed on any warm-blooded animal that they happen to come across, including humans.

 

Flea Biology

All adult fleas are parasites. They survive by piercing the skin of their host and drawing blood through specially adapted mouthparts.

Fleas undergo complete metamorphosis, meaning that they have four distinct life stages: egg, larva, pupa, and adult. Fleas usually lay their eggs in the fur or hair of a host animal. The eggs are not attached to the animal, so they can shake off quite easily, thus dispersing the eggs over a wide area as the infested animal travels about.

Larval fleas have chewing mouthparts and will eat virtually anything, but thrive on the feces of adult fleas, which contains undigested or partially digested blood. After pupation, the fleas emerge as adults. Adult fleas can survive without a meal for a considerable time; they will frequently lie in wait for a suitable animal to pass by, and then jump onto the animal when it does. Female fleas cannot produce eggs, however, until they have taken at least one blood meal.

Fleas are important from a health point of view, since they are associated with the transmission of serious diseases.

Since fleas are so small, many people don't actually notice the insects themselves. Some signs that you may have a flea problem include persistent scratching by household pets, or the appearance of flea bites on family members. Flea bites usually appear as tiny dark red spots. In sensitive individuals, these spots will be surrounded by inflamed, reddened areas. Most commonly these will appear on the feet or legs of adults, but they may appear anywhere on the body -- particularly on children.

You may, however, notice the fleas themselves when walking across infested areas, especially while wearing light-colored colored clothing. Adult fleas will often jump onto people or animals walking by, and they are quite easy to notice against light-colored clothes.