Tick identification guide
Tick Identification Chart: Common U.S. Ticks
Body color alone is rarely enough to identify a tick. Compare the shield pattern, mouthpart length, body shape, life stage, and where the tick was found.
Ixodes scapularis
Blacklegged (deer) tick
- Markings
- Small, reddish-brown to black, with no ornate white markings. Unfed nymphs can be about the size of a poppy seed.
- Range
- Eastern and central United States
Full species guide →
Ixodes pacificus
Western blacklegged tick
- Markings
- Dark legs and a reddish-brown body without ornate white markings; closely resembles the eastern blacklegged tick.
- Range
- Pacific Coast, especially northern California
Full species guide →
Amblyomma americanum
Lone star tick
- Markings
- Reddish-brown. Adult females usually have one distinct pale dot on the back; adult males have pale markings around the body edge.
- Range
- Southern, eastern, and midwestern United States
Full species guide →
Dermacentor variabilis
American dog tick
- Markings
- A larger brown tick with mottled cream or gray markings on the shield behind the mouthparts.
- Range
- Widely distributed east of the Rocky Mountains and in parts of the Pacific Coast
Full species guide →
Dermacentor andersoni
Rocky Mountain wood tick
- Markings
- Brown with ornate pale markings; adults resemble American dog ticks, making geography and close dorsal photos important.
- Range
- Rocky Mountain states and southwestern Canada
Full species guide →
Rhipicephalus sanguineus
Brown dog tick
- Markings
- Uniform reddish-brown without ornate markings; has a narrow, elongated body and is strongly associated with dogs and kennels.
- Range
- Worldwide, often in and around buildings where dogs live
Full species guide →
Amblyomma maculatum
Gulf Coast tick
- Markings
- Long mouthparts and ornate pale markings; adults are often found on larger animals and people.
- Range
- Atlantic and Gulf Coast states, with an expanding inland range
Full species guide →
What to compare
- ◆Pale or white markings on the back
- ◆Long versus short mouthparts
- ◆Overall body shape
- ◆Approximate size before or after feeding
- ◆Geographic range and where the tick was found
Why identification can be difficult
- ◆Nymphs can be extremely small
- ◆Feeding changes a tick's color and proportions
- ◆Damage or a poor camera angle can hide key markings
- ◆Several species look similar without a sharp dorsal photo
Reference: CDC tick guidance. Tick ranges and public-health guidance can change; consult the linked source for current information.