Types of Ticks: How to Identify the Ticks That Bite in the US

How many types of ticks are there?

Scientists have described more than 900 kinds of ticks, UC IPM says, and about 80% of them are hard ticks. Only a small share bite people. In the lower 48 states, the CDC maps eight types of ticks that spread disease to humans. Five of those make up most of the ticks people find on themselves and their pets.

Each state has its own short list, too. California has 48 kinds of ticks, but only 6 attach to people with any regularity, according to UC IPM. Minnesota has about a dozen, and Tennessee at least 15. On iNaturalist, naturalists have photographed 38 tick species in the US with an expert-confirmed name (read October 23, 2026).

Hard ticks vs soft ticks

All ticks belong to two main families. Hard ticks (Ixodidae) have a flat shield on the back and feed for days. Soft ticks (Argasidae) have no shield, look leathery, and feed for less than an hour, usually at night. In practice, nearly every tick you find on a person, a dog or a deer is a hard tick.

What are the three types of ticks?

The question has two common answers. First, the three ticks behind most tick-borne illness in the US are the blacklegged tick, the American dog tick and the lone star tick. Minnesota’s health department and the PA Tick Research Lab both name those three.

Second, “three types” sometimes means the three life stages that bite: larva, nymph and adult. Larvae have 6 legs and are barely bigger than a printed period. Nymphs have 8 legs and are about the size of a poppy seed. Our guide to what a tick looks like at each stage shows all three to scale.

Tick identification chart: the one mark that names each tick

Most types of ticks in the US can be named by one mark on the shield behind the head of an adult female. Check for a white dot, a black shield on an orange body, or cream or silver marbling. Then use size, the length of the mouthparts, and where you live to settle it. The chart below puts that mark first.

Sizes from Texas A&M AgriLife, UC IPM, Oak Ridge National Laboratory, Penn State Extension and the University of Alberta museums. Ranges and diseases from the CDC. Males and engorged females look different.

How to identify a tick in five checks

To identify a tick, work from the body plan down to the details. First confirm it is a tick, then find the shield, read its marks, and check the mouthparts and legs. Finally, add your location. Tick experts on Reddit ask for the location before anything else, because it rules out most of the look-alikes.

Deer tick or dog tick?

These are the two types of ticks people mix up most, and the shield settles it. A female deer tick has a solid black shield on a red-orange body and is about half the size of a dog tick. A female dog tick has a cream, marbled shield on a dark brown body. Our side-by-side guide to telling a deer tick from a dog tick covers males, nymphs and fed ticks of both.

What a photo can and cannot tell you

A sharp photo of the top of an unfed adult is enough to name most types of ticks. Nymphs are harder, because their marks are faint, and larvae need a microscope. So when you photograph a tick, put it on white paper, shoot the top in daylight, and note the state where you found it.

Fed ticks are the hardest case. An engorged female swells into a gray bean, and the body color disappears. Look at the small shield behind the head instead, because the marks stay there. Even then, people misread fed ticks: in one 2025 r/ticks thread, a doctor called a tick a female deer tick, while the volunteers identified the same photo as a lone star nymph.

One rule has no exceptions: a photo of a bite cannot tell you which tick bit you. Save the tick itself in a sealed bag or taped to a card. You can also try our free photo bug identifier on the tick.

The five types of ticks that bite people most

Five hard ticks are behind most tick bites in the US: the blacklegged, lone star, American dog, western blacklegged and Gulf Coast ticks. The first three alone make up 80% of the 59,349 expert-confirmed US tick sightings on iNaturalist. Meanwhile, the other two lead in their own regions.

Blacklegged tick (deer tick)

The blacklegged tick is small and dark, and the female is the easiest tick to recognize: a black shield on a red-orange body, with black legs. It is the tick most linked to Lyme disease. Adults stay active on any winter day above freezing, so it is the tick you may find in November or even January.

Scientific name

Ixodes scapularis

Size, unfed adult female

2 to 3 mm (about 1/8 in); a nymph is about 1.5 mm, the size of a poppy seed

The mark to look for

Black shield on a red-orange body, black legs, no white marks

Where it lives

The eastern US, from New England and the upper Midwest south to Florida and Texas

When it bites

Nymphs in late spring and summer; adults in fall, early spring and warm winter days

Main disease risk

Lyme disease, anaplasmosis, babesiosis, Powassan virus

Full guide

Deer tick guide: size, bites and Lyme risk

One popular summary gets this tick backward. Google’s AI Overview for this topic says the female has “a dark body with a reddish-orange cap near the head”. It is the other way around: the dark shield sits near the head, and the red-orange body is behind it.

Lone star tick

The lone star tick is a round, reddish-brown tick, and the female carries a single white or silver dot in the middle of her back. The CDC calls it a very aggressive biter. All three stages bite people, and the nymphs and adult females bite most often.

Scientific name

Amblyomma americanum

Size, unfed adult female

1/8 to 1/4 in (3 to 6 mm), depending on the source

The mark to look for

One white dot on the female's back; the male has faint white marks on the rear edge instead

Where it lives

The South, East and Midwest, now north to coastal Maine

When it bites

March to August, with a peak in May and June

Main disease risk

Ehrlichiosis, Heartland and Bourbon viruses, tularemia; linked to alpha-gal syndrome (red meat allergy)

Full guide

Lone star tick guide: the white dot and meat allergy

Sources disagree on its size. Oak Ridge National Laboratory and the PA Tick Research Lab put adults at about 1/8 inch (3 mm), while Texas A&M gives unfed females 4 to 6 mm. Either way, it is larger than a deer tick and about the size of a dog tick.

American dog tick (wood tick)

The American dog tick is the largest common US tick, at about 3/16 inch (4 to 5 mm) before it feeds. The female has a cream or silver marbled shield on a dark brown body, and the male is marbled all over. In the North people call it the wood tick. A fed female can swell to about 1/2 inch, the size of a small grape.

Scientific name

Dermacentor variabilis

Size, unfed adult female

About 3/16 in (4 to 5 mm); up to 1/2 in (15 mm) when fed

The mark to look for

Cream or silver marbled shield, short mouthparts

Where it lives

East of the Rocky Mountains, plus parts of the Pacific Coast

When it bites

April to July; adult females bite most in spring and early summer

Main disease risk

Rocky Mountain spotted fever, tularemia; it does not spread Lyme disease

Full guide

Dog tick guide: the American dog tick and wood tick

It is also the tick people photograph most. On iNaturalist, it accounts for 39% of confirmed US tick sightings, and more than half of those in New England and the Great Lakes states. For dogs that come home with ticks, see our guide to finding and removing ticks on dogs.

Western blacklegged tick

The western blacklegged tick is the West Coast twin of the deer tick, with the same black shield, red-orange body and black legs. It is the main Lyme carrier in California, Oregon and Washington. Unlike most ticks, it is active mainly from late fall through spring.

Scientific name

Ixodes pacificus

Size, unfed adult female

About 1/8 in (3 mm); a nymph is about 1/25 in (1 mm)

The mark to look for

Black shield on a red-orange body, black legs; only on the Pacific side of the country

Where it lives

The Pacific Coast, mainly northern California; also parts of Oregon, Washington, Nevada, Utah and Arizona

When it bites

Adults from November to April; nymphs in spring and early summer

Main disease risk

Lyme disease, anaplasmosis, hard tick relapsing fever

It is the most widespread tick in California, found in 56 of the state’s 58 counties, says UC IPM. LymeDisease.org gives 55. It bites people more often than any other California tick, yet fewer carry Lyme bacteria. One reason is its nymphs feed mostly on lizards: the western fence lizard has a blood protein that kills Lyme bacteria, the National Park Service notes.

Gulf Coast tick

The Gulf Coast tick looks like a dog tick at first glance, with a pale, ornate shield. Its mouthparts are longer and narrower, though, and the shield has reddish-brown streaks. It is a late-summer tick, so a marbled tick in July or August in the South is more likely this one than a dog tick.

Scientific name

Amblyomma maculatum

Size, unfed adult female

1/8 to 1/4 in (3 to 7 mm); up to 3/4 in (18 mm) when fed

The mark to look for

Pale shield with reddish-brown streaks, long mouthparts

Where it lives

About 100 to 150 miles inland along the Gulf and southern Atlantic coasts, from Texas to South Carolina; also Oklahoma, Kansas and Arkansas

When it bites

June to September, with the peak in July and August

Main disease risk

Rickettsia parkeri rickettsiosis, a form of spotted fever

It is common where it lives. In Texas, Louisiana and Mississippi, it is the most photographed tick on iNaturalist, ahead of the lone star tick. Texas A&M notes that recent studies found more than 20% of Gulf Coast ticks carry Rickettsia parkeri, and that the tick is spreading north and inland.

Other hard ticks in the US

Beyond the big five, five more types of ticks matter in parts of the US. The Rocky Mountain wood tick lives at high elevation in the West. Along the West Coast live the Pacific Coast and western dog ticks. The brown dog tick lives indoors with dogs, and the Asian longhorned tick is a newcomer in the East.

Rocky Mountain wood tick

The Rocky Mountain wood tick looks almost the same as the American dog tick, with a silver-gray marbled shield. Range is the easiest way to tell them apart: the CDC places it in the Rocky Mountain states and southwestern Canada at 4,000 to 10,500 feet (1,200 to 3,200 m). It is most active from March to June.

Scientific name

Dermacentor andersoni

Size, unfed adult female

1/8 to 3/16 in (3 to 5 mm); up to 5/8 in (16 mm) when fed

The mark to look for

Silver-gray marbled shield; found in mountains and foothills

Where it lives

Montana, Wyoming, Idaho, Colorado, Utah and neighboring states, at elevation

When it bites

March to June, with the peak in May

Main disease risk

Colorado tick fever, Rocky Mountain spotted fever, tularemia; can cause tick paralysis

Pacific Coast tick and western dog tick

On the West Coast, two marbled ticks replace the American dog tick. The Pacific Coast tick (Dermacentor occidentalis) is the tick photographed most in California, at 49% of confirmed sightings there. UC IPM says it alone spreads Rickettsia philipii, which leaves a painful scab at the bite.

The western dog tick (Dermacentor similis) was only recently described as a separate species. Before that, the dog ticks west of the Rockies were counted as American dog ticks. The CDC now lists it beside the American dog tick and says more research is needed on what it spreads.

Brown dog tick

The brown dog tick is the one type of tick that can live and breed indoors. It is plain reddish brown with no markings and a narrow body, about 1/8 inch (3 mm) long. Dogs are its main host at every stage, and it often turns up crawling up walls and curtains in homes and kennels.

Scientific name

Rhipicephalus sanguineus

Size, unfed adult female

About 1/8 in (3 mm); a fed female grows to about 1/2 in

The mark to look for

No marks at all; uniform reddish brown and narrow

Where it lives

Worldwide; in most of the US inside homes and kennels, and outdoors in warm southern areas

When it bites

All year indoors

Main disease risk

Rocky Mountain spotted fever in the southwestern US and along the Mexico border; serious dog diseases

A female can lay up to 4,000 eggs indoors, Texas A&M says, so one tick on a dog can turn into a house problem. Our brown dog tick guide covers how to clear it.

Asian longhorned tick

The Asian longhorned tick is a small, plain light-brown tick from East Asia, first found in the US in 2017 in New Jersey. US populations are all female. Each female lays eggs without mating, so one tick can start a colony. The CDC says thousands may be found at once in grass or on one animal.

Scientific name

Haemaphysalis longicornis

Size, unfed adult female

About 1/10 in (2.5 mm); the size of a pea when fed

The mark to look for

No marks; small and light brown, often found in large numbers

Where it lives

The East, from New York south to Georgia and west to Missouri; CDC listed 20 states by April 2024

When it bites

March to November, with most sightings in June and July

Main disease risk

No human disease proven in the US yet; it is not a Lyme carrier. A serious livestock pest

It bites people less often than native ticks, the CDC says. It also cannot spread Lyme bacteria, according to USDA APHIS. Its threat so far is to cattle, sheep and other animals. If you think you found one, seal it in a bag and send it to your state extension office or vet, because it is still being mapped.

Soft ticks: relapsing fever, bat and bird ticks

Soft ticks are the rarer types of ticks for most Americans. They have no shield, a wrinkled body, and mouthparts hidden underneath. Instead of waiting in grass, they live in the nests of their hosts and bite for less than 30 minutes, usually at night. Most people never notice the bite.

Relapsing fever ticks

Soft ticks of the genus Ornithodoros spread soft tick relapsing fever. In the US, the CDC says, most people are infected while sleeping in rodent-infested cabins in western mountains. The ticks hide in the walls and come out at night, even in winter, when a fire warms the cabin.

A second kind lives in caves, mostly in Texas. The illness brings fever, headache and muscle aches 4 to 21 days after the bite. Usually, the fever lasts about 3 days, fades for about a week, and then returns, which gives the disease its name.

Bat ticks

The bat tick (Carios kelleyi) lives with bats in attics, barns and church belfries. Rutgers researchers note it has been found in 29 of the 48 lower states. It usually stays with the bats. However, once the bats leave or are removed, hungry ticks wander and sometimes bite people.

Iowa State Extension says the fix starts with sealing the bats out, and the ticks can survive months or even years without a meal. For that reason, it may also take a crack-and-crevice treatment in the roost area, following the product label.

Bird, poultry and ear ticks

The fowl tick (Argas persicus), called the “blue bug”, lives in the cracks of chicken coops. It feeds on birds at night and hides by day. Oklahoma State Extension calls it a serious poultry pest that can kill chicks through blood loss. Its relatives live in pigeon, swallow and seabird nests.

One more soft tick turns up on dogs, horses and cattle: the spinose ear tick (Otobius megnini). It lives deep in the ear canal, mostly in dry country west of the Mississippi. Only the larvae and nymphs feed, according to the Companion Animal Parasite Council, and the adults do not feed at all.

Which types of ticks carry Lyme disease and other illnesses?

In the US, only two ticks spread Lyme disease to people: the blacklegged (deer) tick in the East and Midwest, and the western blacklegged tick on the Pacific Coast. The lone star tick and the American dog tick do not. Other types of ticks carry different diseases, so the type matters if you get sick.

Which ticks carry Lyme disease?

Only Ixodes ticks, the blacklegged and western blacklegged ticks, carry Lyme bacteria to people in the US. Even then, most of them are not infected. Our deer tick guide covers how long a tick must feed before it can pass on Lyme bacteria, and what the numbers mean for you.

Infection rates vary a lot by place. The Minnesota Department of Health says about 1 in 3 adult blacklegged ticks there carry Lyme bacteria, and 1 in 5 nymphs. In northern California, by contrast, UC IPM puts it at 1% to 2% of adult western blacklegged ticks and 2% to 15% of nymphs.

Which ticks should you worry about?

The most dangerous tick is the one carrying a germ that is common where you live. Rocky Mountain spotted fever, spread by dog ticks, wood ticks and brown dog ticks, can be deadly if not treated early, the CDC warns. Powassan virus, from deer ticks and groundhog ticks, is rare but can cause swelling of the brain.

Diseases from the CDC, except Pacific Coast tick fever, from UC IPM. A tick that can carry a disease is not always infected.

A few ticks cause harm without any germ. The saliva of some ticks, most often dog and wood ticks (Dermacentor), can cause tick paralysis, a weakness that climbs up the body. The CDC says people usually start to move normally within 24 hours of removing the tick.

Medical disclaimer. This page is for general information only. It is not a medical diagnosis. If you have severe symptoms, trouble breathing, swelling of the face or throat, fast spreading redness, fever, severe pain, pus, or signs of infection, contact a doctor or your local emergency number.

Which ticks live in my state?

The types of ticks you meet depend on your region. In New England and the Great Lakes states, the American dog tick and the deer tick make up nearly all sightings. From Virginia to Texas, the lone star tick leads. On the West Coast, the Pacific Coast tick and the western blacklegged tick lead.

We read all 59,349 research-grade US tick sightings on iNaturalist on October 23, 2026, and grouped them by region. The CDC’s range maps, Texas A&M and UC IPM fill in the ticks that people rarely photograph.

Percentages are each tick’s share of research-grade iNaturalist tick sightings in that region. They show what people photograph, mostly outdoors, not how often each tick bites. Brown dog ticks live indoors and are photographed far less often than they are found.

Are there ticks in Florida and Texas?

Yes, and plenty of them, all year in places. In Florida, the lone star tick is 54% of iNaturalist sightings, followed by the Gulf Coast tick (21%) and the blacklegged tick (12%). In Texas, the Gulf Coast tick leads at 47%, then the American dog tick and the lone star tick. The brown dog tick is common in both states, in homes with dogs.

Are there ticks in Colorado and Utah?

Yes. The Rocky Mountain wood tick is the main tick of the high country, at 67% to 74% of sightings in Montana, Wyoming and Utah. In Colorado, the American dog tick is common on the eastern plains, while the wood tick takes over in the foothills and mountains. Both are marbled and hard to tell apart, so the place is the best clue. Ticks there are most active from March to June.

Are there ticks in California, Oregon and Washington?

Yes, and they are common along the West Coast, mostly in grass, brush and oak woodland. California has the Pacific Coast tick, the western blacklegged tick and the western dog tick. In Washington, the Rocky Mountain wood tick makes up about 1 in 5 sightings as well. Most West Coast tick sightings come between January and May, earlier than in the East.

Ticks in Michigan, Pennsylvania and the North

In Michigan, the American dog tick is 72% of sightings and the blacklegged tick 26%. Pennsylvania and New York are nearly an even split between the two, with the lone star tick and the Asian longhorned tick now turning up as well. In fact, Pennsylvania is one of the few states where the deer tick is the most photographed tick. About 15 kinds of ticks live in the Northeast, the National Park Service says, but most feed only on bats, rabbits, moose or birds.

Does Hawaii have ticks? Does Alaska?

Hawaii has the brown dog tick, the CDC notes, plus seabird ticks on its coasts, but none of the mainland ticks that spread disease. Alaska has no established populations of the human-biting ticks on the CDC’s maps. Ticks in Alaska mostly live on wild animals, and a few arrive on pets or travelers. Still, brown dog ticks can infest a home with dogs even in Alaska, the Companion Animal Parasite Council notes.

Which states have the worst ticks?

It depends on what “worst” means. For Lyme disease, Mayo Clinic points to the Northeast, Minnesota, Wisconsin and the areas around Lake Michigan, where deer ticks are common. In 2015, 95% of confirmed Lyme cases came from the Northeast, Wisconsin and Minnesota, says the National Park Service. If you mean sheer numbers of aggressive biters, the lone star belt from Virginia to Missouri and Texas is hard to beat. Rocky Mountain spotted fever, by contrast, occurs across the whole country, the CDC says.

When each type of tick is active

Most types of ticks peak in May and June, when 45% of US tick sightings happen. Three break the pattern. The Gulf Coast tick peaks in July and August, and the blacklegged tick has a second peak in October and November. Out West, the western blacklegged tick is active mostly from November to April.

The calendar is built from the month of each confirmed sighting, so read it as a rough guide. Local weather shifts it by weeks. Adult deer ticks look for a host on any winter day above freezing, the CDC says, and a warm spell in January can bring them out.

The season also changes which tick you are likely to have. A small dark tick in November in the North is almost always a deer tick. A marbled tick in August on the Gulf Coast is more likely a Gulf Coast tick than a dog tick. Finally, a flood of tiny ticks in late summer is usually a hatch of seed ticks, the larvae.

Three mix-ups in popular tick guides

• Myth 1

  Myth: “The female deer tick has a red-orange cap near the head.”

  Truth: Reversed. The shield near the head is black, and the red-orange part is the body behind it. Google's AI Overview for this topic says it backward.

• Myth 2

  Myth: “The lone star tick is rarely seen in Tennessee.”

  Truth: Oak Ridge National Laboratory's tick guide still says so. Today it is the most reported tick in Tennessee, at 45% of iNaturalist sightings, and the CDC maps the whole state inside its range.

• Myth 3

  Myth: “The deer tick spreads Borrelia hermsii relapsing fever.”

  Truth: LymeDisease.org lists it that way. The CDC says Borrelia hermsii comes from the soft tick Ornithodoros hermsi in western cabins. The deer tick spreads a different relapsing fever germ, Borrelia miyamotoi.

Found a tick? What to do next

If a tick of any type is attached, remove it first and identify it after. Grip it close to the skin with fine-tipped tweezers and pull straight out with steady pressure. Then save it in a sealed bag or tape. The type of tick matters later, if a rash or fever starts.

The CDC’s removal steps are short. Don’t twist or jerk the tick, and don’t use nail polish, petroleum jelly or heat. Clean the bite and your hands afterward. Our step-by-step guide to removing a tick safely covers a tick with its head stuck in the skin.

After that, prevention is the same for all types of ticks. Repellent on skin, permethrin-treated clothes and a full tick check after time outdoors do most of the work. Our guide on how to prevent tick bites covers each step, and our page on getting rid of ticks in the yard and house covers the rest. For an overview of tick biology, start at our guide to ticks.

The brown dog tick is the one type that needs work indoors: treat the dog through your vet and the house at the same time, as our guide to clearing brown dog ticks explains.

Pest control disclaimer. Photo-based identification can help, but it is not always perfect. For dangerous spiders, large infestations, or anything you are unsure about, contact a licensed pest control professional.