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 ...

Medically reviewed by Renita White, MDMedically reviewed by Renita White, MD Pubic lice (Pthirus pubis), also known as crabs, ...

Head lice feed only on humans. Head lice are blood-sucking insects about the size of a sesame seed and are tan to grayish-white in color. They attach themselves to the skin of the head (scalp ...