Lice are parasitic insects that feed on blood and can live in peoples heads and on their bodies, including in the pubic area. Head lice often are a concern for parents of young children. Lice crawl, not hop or fly, and are spread commonly through head-to-head contact. A child with lice will experience itching, difficulty sleeping, and sores on the head. The child also might feel like something is moving in his hair. Prescription and over-the-counter shampoos, plus a special comb with tight teeth, work best to kill lice and remove their eggs, called nits.