Dermacentor variabilis, commonly known as the American dog tick, is a species of tick found primarily in the eastern and central United States. It is characterized by a brownish color with white markings on its back. This tick typically feeds on the blood of mammals, including dogs and humans, and is most active in the spring and summer months. These ticks are known vectors for several diseases, including Rocky Mountain spotted fever and Tularemia. They thrive in grassy and wooded areas, making outdoor activities a potential risk for tick bites. Proper tick prevention measures, such as using repellents and checking for ticks after outdoor exposure, are essential for reducing the risk of disease transmission.