As much as the thought of lice may disgust you, the fact is that if you have a child, and they have hair, they can get lice. It has nothing to do with cleanliness or housekeeping abilities. Anyone with hair can get lice. So, let's get to know the enemy.
Head lice are extremely tiny critters than can only live on a human head.
An adult will glue up to ten nits, or eggs, a day onto the hair shafts and continue to do this for about 10 days. After a week, the nits hatch into a nearly invisible nymph stage, and a week later the mature adults begin laying nits. Take a good look at this picture. Lice have 6 legs with hooks on the end. Once these guys get onto a head, they hold on for dear life.