The western black-legged tick, also known as Ixodes pacificus, is a small arachnid commonly found in the western United States. It typically inhabits wooded and grassy areas, where it feeds on the blood of mammals, birds, and reptiles. This tick is most active during the spring and fall months. These ticks are known carriers of various diseases, including Lyme disease and anaplasmosis. They are usually identified by their dark brown or black coloration and can be as small as a pinhead. Proper tick prevention measures, such as using repellents and wearing protective clothing, are essential to reduce the risk of tick-borne illnesses.