The bite is often painless, but this species can transmit Lyme disease and other infections. That transmission risk, rather than venom, is why it is flagged here. Follow CDC removal guidance and contact a clinician if a rash, fever or other concerning symptoms develop afterwards.
We identify, we don't diagnose. If you've been bitten or stung and symptoms develop, or you're worried, seek medical attention.
SizeAdults 3–5 mm unfed, up to 10 mm engorged; nymphs 1–2 mm
MarkingsEight legs as an adult — it is an arachnid, not an insect, and this rules out bed bugs and lice · Flat and seed-shaped when unfed; grey and swollen when engorged
WhereLong grass, leaf litter, woodland edge and the boundary between lawn and brush. They wait on vegetation and grab a passing host.
SeasonNymphs peak late spring to midsummer; adults in autumn and mild winter spells
How to tell it apart
Eight legs as an adult — it is an arachnid, not an insect, and this rules out bed bugs and lice
Flat and seed-shaped when unfed; grey and swollen when engorged
Blacklegged tick: reddish body with a solid dark shield behind the head, dark legs
Nymphs are poppy-seed sized and account for most transmission
No wings at any stage, and it crawls rather than jumps or flies
Where you’ll find it
The blacklegged tick covers the eastern and upper midwestern US, with a western relative on the Pacific coast. Other species with other risks cover the rest of the country.
Long grass, leaf litter, woodland edge and the boundary between lawn and brush. They wait on vegetation and grab a passing host.
Nymphs peak late spring to midsummer; adults in autumn and mild winter spells.
How it behaves
It does not jump, fly or drop from trees. It quests — climbs vegetation, holds out its front legs and waits for something to brush past. Once on a host it walks to a sheltered spot, cuts the skin and cements itself in place, which is why removal takes a tool rather than a tug. Transmission risk generally rises the longer it stays attached, which is what makes prompt removal the single most useful thing you can do.
What a bite looks like
Often nothing at first beyond the attached tick. A small red mark may follow. An expanding circular or bull's-eye rash appearing days to weeks later is a recognised sign of Lyme disease and is not an allergic reaction to the bite.
Often painless, which is why ticks are usually found by sight rather than by feel.
We identify, we don't diagnose, and this is the record where that matters most. CDC advises contacting a clinician if you develop a rash or fever within days to weeks after removing a tick. Not everyone with Lyme disease develops the same rash, so do not use this page to rule an infection in or out.
A skin mark cannot confirm which animal caused it. Read the bug bite and sting guide for the limits and the symptoms that should end an online search.
You’ve found one indoors
Remove it promptly with fine-tipped tweezers: grasp as close to the skin as possible and pull steadily upward without twisting or crushing the body. Do not use heat, petroleum jelly or nail varnish. Clean the bite area and your hands, then follow CDC advice if symptoms develop.
Common questions
How do I remove a tick correctly?
Fine-tipped tweezers, as close to the skin as you can get, steady upward pressure, no twisting. Then clean the bite area and your hands. CDC advises against heat, petroleum jelly and nail polish.
Is it a tick or a bed bug?
Count the legs. Ticks have eight and are arachnids; bed bugs have six. The distinction matters because only one of them carries disease risk.
Do all ticks carry Lyme disease?
No. Lyme is associated chiefly with blacklegged ticks, and only a proportion of those carry it. Other species transmit different infections, so the species and the region both matter.
Do ticks drop out of trees?
No. They quest from low vegetation and grab a passing host. That is why bites are usually on the lower body first, and why they are picked up at the edges of paths rather than under canopy.
Étienne Lacroix-Carignan · CC0