Skip directly to search Skip directly to A to Z list Skip directly to navigation Skip directly to site content Skip directly to page options
CDC Home
Two lice viewed under an electron microscope.

Adult head lice are roughly 2–3 mm long. Head lice infest the head and neck and attach their eggs to the base of the hair shaft. Lice move by crawling; they cannot hop or fly.

Head lice infestation, or pediculosis, is spread most commonly by close person-to-person contact. Dogs, cats, and other pets do not play a role in the transmission of human lice.

Both over-the-counter and prescription medications are available for treatment of head lice infestations.

Image: Two lice viewed under an electron microscope. Note the claws used to grasp onto individual hairs. Credit: CDC

Explore

 
Contact Us:
  • Centers for Disease Control and Prevention
    1600 Clifton Rd.
    Atlanta, GA 30333
  • 1-800-CDC-INFO
    (1-800-232-4636)
    TTY: 1-888-232-6348
    Hours of Operation
    8am-8pm EST/ Monday-Friday
    Closed Holidays
  • Contact CDC-INFO
  • Page last reviewed: September 24, 2013
  • Page last updated: September 24, 2013
USA.gov: The U.S. Government's Official Web PortalDepartment of Health and Human Services
Centers for Disease Control and Prevention   1600 Clifton Rd. Atlanta, GA 30329-4027, USA
800-CDC-INFO (800-232-4636) TTY: (888) 232-6348 - Contact CDC-INFO