Six tick species are established in Tennessee, and knowing which one you’re looking at matters because each carries different diseases. The most common species you’ll encounter are the lone star tick, the American dog tick, and the blacklegged tick (also called the deer tick), but three others, including a recently arrived invasive species, round out the list. Here’s how to tell them apart.
Lone Star Tick
The lone star tick is one of the most frequently encountered ticks in Tennessee, and it’s also the most aggressive. Unlike other species that wait on vegetation for a host to brush past, lone star ticks actively pursue people and animals. Adult females are the easiest tick in the state to identify: they have a round, reddish-brown body with a single bright white dot in the center of their back. Males are smaller, lack the dot, and instead have faint white streaks or spots along the edges of their body.
Lone star ticks are active from spring through fall and are found statewide, though they’re especially common in wooded and brushy areas across the southeastern U.S. They carry a longer list of diseases than any other Tennessee tick: ehrlichiosis, tularemia, Heartland virus, and STARI (Southern Tick-Associated Rash Illness). They’re also the tick linked to alpha-gal syndrome, a condition that triggers allergic reactions to red meat. Alpha-gal syndrome develops after repeated bites and can cause hives, digestive problems, or in severe cases, anaphylaxis hours after eating beef, pork, or lamb.
American Dog Tick
The American dog tick is the large, flat tick you’re most likely to notice on your clothing or skin after a walk in tall grass. Adults are brown to reddish-brown with distinctive gray or silver markings on their back shield. Unfed females measure about 5 mm (roughly the size of a sesame seed), while males are slightly smaller at around 3.6 mm. The easiest way to distinguish males from females: the male’s shield covers nearly the entire back, while the female’s shield is a small plate just behind the head. When fully engorged after feeding, females can swell to 15 mm long and 10 mm wide, roughly the size of a small grape.
Immature stages (larvae and nymphs) are much harder to spot. Larvae are tiny, about 0.6 mm, and yellow before feeding, turning gray to black once engorged. Nymphs are slightly larger and pale yellowish-brown. Neither immature stage has the white markings that make adults recognizable.
This species carries Rocky Mountain spotted fever and tularemia. It’s the primary vector of Rocky Mountain spotted fever in the eastern U.S., and its highest risk period in Tennessee is spring and summer. Despite the name, this tick feeds on people just as readily as dogs.
Blacklegged Tick (Deer Tick)
The blacklegged tick is the one Tennesseans should pay closest attention to for Lyme disease risk. Established populations are concentrated primarily in Middle and East Tennessee, including many counties around the Nashville metro area and extending eastward toward the Appalachian region. This tick is expanding its range in the state, so even areas that were historically low-risk may now have populations.
Blacklegged ticks are noticeably smaller than American dog ticks. Adults are about 3 mm unfed, with a dark brown or black shield and a reddish-orange body. Their legs are dark, which gives the species its common name. Males are uniformly dark. These ticks lack the bold white or silver patterning seen on American dog ticks and lone star ticks, making them look plainer overall.
Beyond Lyme disease, blacklegged ticks also transmit anaplasmosis, babesiosis, and Powassan virus. A critical difference from other Tennessee ticks: blacklegged ticks can bite any time temperatures are above freezing. That means they remain active during mild winter days when you might not expect tick exposure at all.
Brown Dog Tick
The brown dog tick is unusual because it can complete its entire life cycle indoors. It’s the only Tennessee tick that thrives inside homes, kennels, and dog runs. As the name suggests, it primarily feeds on dogs, but it will bite humans when dog hosts aren’t available.
This tick is uniformly reddish-brown with no distinctive markings, making it one of the harder species to identify at a glance. It’s smaller and narrower than the American dog tick, and it lacks the silver or white patterning. If you’re finding ticks inside your home, especially around dog bedding or along baseboards, brown dog ticks are the most likely culprit. They transmit Rocky Mountain spotted fever.
Gulf Coast Tick
The Gulf Coast tick is found across the southeastern and mid-Atlantic states, including Tennessee. Adults have a somewhat ornate appearance with faint light markings on the shield, though they’re less dramatic than the bold silver patterns on American dog ticks. This species mostly feeds on birds and wildlife, so human bites are less common than with lone star or American dog ticks. When it does bite people, it can transmit Rocky Mountain spotted fever.
Asian Longhorned Tick
The Asian longhorned tick is an invasive species recently found in eastern Tennessee. It’s small, reddish-brown, and has no markings on its back, which makes it easy to confuse with a brown dog tick or an immature tick of another species. One distinguishing feature is a noticeable spur on the base of its mouthparts, though this requires a close look or magnification.
What makes this tick remarkable is its ability to reproduce without mating. A single female can produce viable offspring on her own, which means one tick can establish an entirely new population. This leads to explosive infestations: livestock and wildlife can become covered in hundreds or thousands of ticks. The species feeds on cattle, sheep, goats, horses, dogs, wildlife, and humans, and tends to attach on the underside of animals rather than around the head and ears where other ticks are commonly found.
No human diseases have been linked to this tick in the U.S. so far. However, in its native range in East Asia, it transmits several pathogens, so researchers are monitoring it closely. For livestock owners in eastern Tennessee, heavy infestations can cause anemia and stress in animals even without disease transmission.
Quick Comparison by Appearance
- Lone star tick: Reddish-brown, round body. Females have a single white dot center-back. Aggressive biters.
- American dog tick: Brown with bold gray/silver markings on the back shield. Largest common species. Males have the shield covering most of the back.
- Blacklegged tick: Small, dark legs, reddish-orange body with a dark brown/black shield. No bold patterning. Active in cold weather.
- Brown dog tick: Uniformly reddish-brown, no markings. Narrow body. Found indoors.
- Gulf Coast tick: Faint ornate markings on shield. Primarily feeds on wildlife.
- Asian longhorned tick: Small, plain reddish-brown, no markings. Found in large numbers on livestock in eastern Tennessee.
When Each Species Is Active
American dog ticks and lone star ticks are most active in spring and summer, roughly April through August. These are the two species you’re most likely to pick up on a hike during warm months. Blacklegged ticks follow a different pattern entirely. Adults are most active in fall and early spring, and they’ll seek a host on any day the temperature rises above freezing, even in January. Nymphs, which are tiny and easy to miss, peak in late spring and early summer. Brown dog ticks can be active year-round indoors since they aren’t dependent on outdoor temperatures.
Where in Tennessee to Expect Them
Lone star ticks and American dog ticks are found across the entire state, in forests, grasslands, parks, and suburban yards with tall vegetation. Blacklegged tick populations are densest in Middle and East Tennessee, particularly in the counties surrounding Nashville and through the Appalachian region heading east. If you live in West Tennessee, blacklegged tick encounters are less common but not impossible.
Asian longhorned ticks have been documented in eastern Tennessee so far. Gulf Coast ticks are present but less evenly distributed. Brown dog ticks follow dogs, so they can show up anywhere there’s a kennel, dog park, or home with pets, regardless of geography.
What to Do With a Tick You Can’t Identify
If you find a tick on yourself, a family member, or a pet and can’t match it to the descriptions above, save it. Place the tick in a sealed plastic bag or small container with a damp cotton ball to keep it from drying out. Your local University of Tennessee Extension office can help with identification. Knowing the species helps determine which diseases are relevant, since symptoms of tick-borne illnesses can overlap and early treatment makes a significant difference in outcomes.