Lice are small wingless insects, well suited to their mode of living. The louse's body looks squashed and flattened, enabling it to lie close to its host's skin. This is ideal for it to obtain the blood which makes up its diet. This is followed by a pumping action of the throat which causes the blood to be sucked up. When not in use the stylets retract neatly into a pocket just behind the mouth.
Meals are frequent and each takes a few minutes.
Once a louse has found a a good blood supply there is little need for it to move, as its food resource is not going to go away. The legs of the lice are therefore, not so much for walking, but more for hanging in there. The body louse can live in the fibres of clothing, leaving only to feed on blood. Air is collected through the nymph's mouth and passes through its digestive system until the gas pressure is great enough to eject the nymph. The hatched nymph looks more or less like a smaller version of the adult.