This is an adult female deer tick, Ixodes dammini. It transmits Lyme disease and babesiosis to humans. (Image courtesy of the Centers for Disease Control and Prevention.)
Review Date 6/30/2019
Updated by: Jacob L. Heller, MD, MHA, Emergency Medicine, Emeritus, Virginia Mason Medical Center, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.