Ixodes scapularis, commonly known as the black-legged tick or deer tick, is a small arachnid found primarily in the eastern and northern United States. This tick is known for its role as a vector for several diseases, including Lyme disease, anaplasmosis, and Babesiosis. Adult ticks are typically active in the fall and spring, while nymphs are most active in the summer. The black-legged tick prefers wooded and grassy areas, where it can attach to hosts such as deer, rodents, and humans. They are usually less than 2 mm in size and can be identified by their dark brown or black coloration. Proper tick prevention measures are essential to reduce the risk of tick-borne illnesses.