Than You Ever Wanted to Know About Head Lice written by and posted with permission of Glenda S. McKinney Life Cycle Head lice are insects. They go through an incomplete metamorphosis, like dragonflies. First they are eggs, which we called nits. If find them much farther down the hair shaft, the eggs are old and already hatched.
Nits are light in color, described in different sources as pearly, grey, whitish, and silvery.
Eggs hatch in 5-14 days. After they are adults, female lice lay 50-100 eggs before they die. The whole life cycle is about a month. Nymphs and adults eat several times a day, injecting an irritating saliva into the wound to prevent coagulation. Scratching the scalp can result in infections.