This photograph shows a "nit" or tiny white egg sack attached to the shaft of a human hair. (Image courtesy of D. Scott Smith, MD, MSc, DTM&H)
Update Date 2/26/2014
Updated by: Neil K. Kaneshiro, MD, MHA, Clinical Assistant Professor of Pediatrics, University of Washington School of Medicine, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.