Color: Dark brown to black body
Legs: 8
Shape: Flat; broad oval
Size: 1/8“
Antennae: False
The blacklegged tick is named for its dark legs, which are a contrast to its pale body. Blacklegged ticks are sometimes called deer ticks.
Unlike many insects that jump or fly, blacklegged ticks rely on a behavior called questing, where they perch on the tips of tall grass or shrubs with their front legs extended to snag a passing host. They are highly sensitive to moisture and spend much of their time tucked into the leaf litter or shaded soil to avoid drying out, which is why they are most active in humid, wooded areas. Once they find a host, they often crawl upward to find thin-skinned, secluded spots—like the backs of knees or the hairline—to begin a feeding process that can last several days.
The primary concern with blacklegged ticks is their role as the leading carrier of Lyme disease, though they also spread increasingly common illnesses like anaplasmosis. Their smallest life stage, the nymph, is particularly dangerous because it is roughly the size of a grain of sand and can easily go unnoticed during a visual check. Furthermore, as mild winters become more frequent, these ticks remain active longer throughout the year and continue to migrate into new geographic regions.
Blacklegged ticks thrive in high-moisture environments, specifically deciduous forests and the shaded margins where woods meet open lawns. Their primary habitat is the leaf litter layer on the forest floor, which provides the consistent humidity they need to survive between blood meals. You are most likely to encounter them in areas with dense ground cover, tall grasses, or woodpiles, as these spots offer both protection from the sun and easy access to hosts like mice and deer.
When in an area where ticks are common, wear long sleeved shirts and pants, preferably light colored so ticks will be easy to detect. Tuck pants into socks. Use a tick repellent. When you return indoors, inspect clothing and skin thoroughly for ticks, including head. Wash clothes immediately.
Blacklegged ticks live in wooded areas, tall grasses, leaf litter, and shrubby vegetation, particularly in the northeastern, mid-Atlantic, and north-central United States. They thrive in moist, humid environments and are commonly found along trails, forest edges, and overgrown yards where they wait on vegetation to attach to passing hosts.
Blacklegged ticks are dangerous because they can transmit serious diseases, including Lyme disease, anaplasmosis, and babesiosis, through their bites. Lyme disease is particularly concerning, as blacklegged ticks are the primary vector for this illness, which can cause long-term health complications if left untreated.
Blacklegged ticks and deer ticks are the same species (Ixodes scapularis). Deer tick is simply the common name used because these ticks often feed on white-tailed deer. Both names refer to the same tick, which transmits Lyme disease and other illnesses in the eastern and central United States.