Adult: The adult louse is about the size of a sesame seed, has six legs, and is tan to grayish-white. In persons with dark hair, the adult louse will look darker. Females lay nits; they are usually larger than males. Adult lice can live up to 30 days on a person's head.
The four tick-borne diseases are 1) borreliosis (including Lyme disease and related conditions), 2) Rocky Mountain spotted fever, 3) ehrlichiosis, and 4) tularemia, which is also known as rabbit fever.
Tick species that transmit Rocky Mountain spotted fever: Rocky mountain wood tick (Dermacentor andersoni), American dog tick (Dermacentor variabilis), Brown dog tick (Rhipicephalus sanguineus).