Tick identification

Which tick
bit you?

Knowing the species tells you the risk — and takes the fear down a notch. Here are the three you’re most likely to meet, at their real size, with what each one can and can’t carry.

Actual size

Smaller than you think.

Every stage, next to a dime. The poppy-seed-sized nymph causes most Lyme cases precisely because it’s so easy to miss.

Specimen plate showing the actual sizes of the deer, lone star, and dog ticks at each life stage, beside a dime and a ruler
No. 1
Specimen illustration of a blacklegged deer tick — dark shield over a reddish-orange body
No. 2

The Lyme carrier

Blacklegged (deer) tick

Ixodes scapularis

Small and dark, with a solid reddish-brown body and no markings. The nymph — the size of a poppy seed — is the one that gets people, because it’s almost impossible to see.

Size. Adult ≈ a sesame seed · nymph ≈ a poppy seed

Where it’s found

What it can carry

This is the tick behind Lyme. If a deer tick was attached to you and it’s been under three days since you removed it, you’re inside the 72-hour window where a single preventive dose can stop Lyme before it starts.

Was it a high-risk bite? Start intake
Specimen illustration of a lone star tick with a single cream-white dot at the center of its back
No. 3

Know it by

Lone star tick

Amblyomma americanum

The female has one unmistakable white dot in the center of her back. Rounder and more aggressive than a deer tick — it will actively come toward a host.

Size. Adult ≈ a sesame-to-apple-seed · nymph is smaller

Where it’s found

What it can carry

The lone star tick does not carry Lyme — a common and important point of confusion. It has its own risks, including the alpha-gal red-meat allergy, so it’s still worth knowing when one bites you.

Specimen illustration of a female American dog tick — ornate marbled shield over a plain dark body
No. 4

Know it by

American dog tick

Dermacentor variabilis

Noticeably larger, brown with ornate off-white or cream mottling on its back. Easier to spot than the others — see it beside them in the size chart.

Size. Adult ≈ a watermelon seed — the biggest of the three

Where it’s found

What it can carry

Does not carry Lyme. It’s a vector of Rocky Mountain spotted fever and tularemia — uncommon but serious, so a dog-tick bite followed by fever and a rash deserves prompt in-person care.

Not sure, or it’s already off?

When in doubt, start there.

If you can’t tell which tick it was, that’s fine — the intake asks a few simple questions and a physician reads it the same day. And if you still have the tick, the field guide shows how to remove and keep it safely.

Start intakeHow to remove a tick
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