Dermacentor is a genus of ticks known for their role as ectoparasites, feeding on the blood of mammals, birds, and reptiles. They are commonly found in grassy and wooded areas, where they attach to hosts to obtain nourishment. Some species within this genus can transmit diseases to both animals and humans. The most notable species of Dermacentor include Dermacentor variabilis, also known as the American dog tick, and Dermacentor andersoni, or the Rocky Mountain wood tick. These ticks are significant in public health due to their ability to carry pathogens such as Rocky Mountain spotted fever and tick-borne encephalitis.