Ixodes scapularis, commonly known as the black-legged tick or deer tick, is a small arachnid found primarily in the eastern and north-central United States. This tick is known for its role as a vector for several diseases, including Lyme disease, which is caused by the bacterium Borrelia burgdorferi. The adult black-legged tick is typically active in the fall and spring, while the nymph stage is most active during the summer. These ticks prefer wooded and grassy areas, where they can attach to hosts such as deer and rodents to feed on blood, which is essential for their reproduction.