Common Human Louse

By Al Lowe
Contributor

Most people haven’t ever had any contact with these insects and there are quite a few myths about them, so here are a few facts.
They are pesky little creatures, only about 1/10 of an inch long. This alone makes them rather hard to find. There are three major types which live on man. The head louse and the body louse are so closely related that most biologists believe that they are variations of the same species. The third one is the crab louse, which is a different animal altogether and lives among the pubic hairs.
The head louse lives mainly among the hairs of the head. It attaches its eggs to hair as well. When these eggs hatch, they form very tiny immature lice which moult several times until they reach their full size. The whole life cycle is spent on man. The body louse is similar, except that it hides in clothing, in seams or crevices.
Lice have no wings at all so they cannot fly. They do, however, have prominent hooks on their legs so they can hang onto hairs or threads. They live entirely on blood which they obtain by sucking. A louse has three tiny tubes which it inserts through the skin to get at the blood. It also has little hooks on its head, with which it attaches itself to the skin while feeding. Each louse takes about one milligram of blood per meal. Both the piercing of the skin and the ‘hanging on’ by the hooks are quite irritating.
Human lice have been with us for a very long time. Lice have been found on Egyptian mummies, dating back several thousand years. They are also very specific about their hosts, that is, human lice will live only on humans, and so on. There are many kinds of lice, on birds and mammals, but each species attacks only a very few kinds of animals, and cannot be passed back and forth - from dogs to humans, for example.
Since these insects cannot fly, they are passed along from one person to another by some form of contact. Head lice are often passed on by using one another’s comb, or hairbrush or by trading hats. Body lice often in clothing or bedding. To avoid getting lice, just exercise normal good personal hygiene.
It is possible for lice to carry diseases. The worst disease spread by them was typhus, which killed millions in the olden times. That disease is now under almost complete control. ‘Trench fever’ in World War 1 was very common, spread by lice. The unsanitary conditions of trench warfare were ideal for the mass production of lice. In modern days, louse-borne diseases have occurred in crowded barracks, in refugee or prisoner-of-war camps. Modern insecticides are completely effective in controlling this pest.
The human louse, Pediculus humanus, has been a scourge of man for many centuries and will be for centuries more, but in a modern society, it is not too hard to keep it under control.