Ixodes scapularis, commonly known as the black-legged tick or deer tick, is a small arachnid found in the eastern United States. It thrives in wooded and grassy areas, primarily feeding on the blood of mammals, birds, and reptiles. Notoriously, it transmits Lyme disease, impacting both wildlife and human populations.

Ixodes scapularis, commonly known as the black-legged tick or deer tick, is native to North America. It is primarily found in the eastern United States, including the Midwest, Northeast, and Southeast regions, as well as parts of southeastern Canada. The distribution extends from Texas and Florida in the south to Maine and Minnesota in the north, and it is also present in parts of Ontario and Quebec in Canada.

Ixodes scapularis typically inhabits areas with moderate to high humidity, which are necessary for its survival. It thrives in deciduous forests, mixed woodlands, and areas with dense vegetation. The tick is often found in leaf litter, on the forest floor, and in grassy or shrubby areas. It requires a habitat that provides sufficient moisture and a suitable microclimate to prevent desiccation.

The ecological niche of Ixodes scapularis involves parasitizing a variety of hosts during its life stages, including mammals, birds, and reptiles. It is especially known for feeding on white-tailed deer, which are key hosts for adult ticks, and small mammals like mice and chipmunks, which are crucial for larval and nymphal stages. The tick plays a significant role in the transmission of pathogens, most notably the bacterium Borrelia burgdorferi, which causes Lyme disease, as well as other tick-borne diseases. Its presence is often associated with fragmented forests and suburban areas where human-wildlife interactions are common.