Adult : 4 pairs of legs, reddish-brown with tiny pits scattered over the back, no antennae, male and female look alike, female when gorged turns grayish black/olive. Nymphs resemble adults except in larval stage when they have an orange colouration and only 3 pairs of legs. Adult : 3mm, with female up to 11mm when engorged with blood.

Eggs (1000-3000) laid in cracks and crevices; 4 nymphal stages.

Related to mites, but with a leathery cuticle. An ectoparasite, it lives on animal blood and usually infest dogs. Can become a very serious problem in homes as it prefers human habitation, usually found crawling on walls and in wall and ceiling joints. Adults can go without feeding for up to 2 years. Females engorge on blood and drop off to lay their eggs.