Head lice begin life as very small (about 0.5-millimeter-in-diameter) eggs called nits, which range in color from white to brown. Nits hatch into young lice called nymphs, which take seven to 10 ...

Although head lice are a year-round problem, the number of cases usually peaks during back-to-school time in the fall and again in January." Patricia Brown, M.D., dermatologist, U.S. Food and Drug ...