Types of Ticks: Identification Chart, Size & ID Guide

Your master ID guide to the common North American ticks — sorted by size, colour, markings, range, and the diseases each one carries.

Quick Answer

Updated July 2026

How do you identify a tick?

Identify a tick by its size, colour, back-plate markings, and range. The five ticks most people meet in North America are the blacklegged (deer) tick, American dog tick, lone star tick, brown dog tick, and Rocky Mountain wood tick. A small reddish-brown tick with solid black legs and no back markings is usually a blacklegged (deer) tick — the one that spreads Lyme disease. A larger brown tick with white or grey marbling on its scutum is an American dog tick or wood tick. A brown tick with a single white dot is a female lone star tick. Life stage matters as much as species: larvae are about 1 mm, nymphs are poppy-seed-sized (1–2 mm) and cause most Lyme cases, and unfed adults are 3–5 mm. Because you cannot tell an infected tick from a clean one by sight, identify it, remove it promptly, and watch the bite.

Tick Identification Chart — 5 Common North American Ticks

Sizes are for unfed ticks; engorged ticks swell to 10 mm or more. Scroll sideways on mobile.

Tick (species)Unfed adult sizeColour & markingsRangeMain disease risk
Blacklegged / deer tick
Ixodes scapularis
~3–4 mm (nymph ~1.5 mm)Reddish-orange rear body, solid dark scutum, uniformly black legs, NO back markingsEastern & Midwest US, Ontario, Quebec, MaritimesLyme disease, anaplasmosis, babesiosis
Western blacklegged tick
Ixodes pacificus
~3–4 mmVery similar to eastern deer tick — dark legs, reddish body, no ornamentationUS Pacific coast, southern BCLyme disease, anaplasmosis
American dog tick
Dermacentor variabilis
~5 mm (up to 10–15 mm engorged)Brown body with white/grey marbling on the scutum; ornate patterningEastern US, parts of the Prairies & OntarioRocky Mountain spotted fever, tularemia
Lone star tick
Amblyomma americanum
~4–6 mmReddish-brown; female has a single white dot on the scutum; long mouthpartsSoutheastern & eastern US, expanding northEhrlichiosis, STARI, alpha-gal (red-meat) allergy
Brown dog tick
Rhipicephalus sanguineus
~3 mm (up to 12 mm engorged)Uniform reddish-brown, elongated body, no clear back pattern; hexagonal baseWorldwide; indoors/kennels across US & CanadaRocky Mountain spotted fever (in some regions)
Rocky Mountain wood tick
Dermacentor andersoni
~5 mm (up to 15 mm engorged)Brown with grey/white mottled scutum; very similar to American dog tickWestern US & Canada (BC, Alberta, Saskatchewan)Rocky Mountain spotted fever, Colorado tick fever, tick paralysis

Species ranges and disease associations per the U.S. Centers for Disease Control and Prevention (CDC) — Ticks and Public Health Ontario — Lyme Disease.

Tick Size by Life Stage

Life stageLegsApprox. size (unfed)Everyday comparison
Larva (seed tick)60.5–1 mmGrain of sand / period on this page
Nymph81–2 mmPoppy seed — causes most Lyme cases
Adult (unfed)83–5 mmSesame to small apple seed
Adult (engorged)810 mm+Grey or brown bean / small grape

By Alex and The Mosquito Team

BuzzSkito Mosquito & Tick Control Specialists · Published July 13, 2026

Disclosure: BuzzSkito may earn a small commission from qualifying purchases made through links on this page, at no extra cost to you. We only point to products we would genuinely use or recommend — the commission never changes our verdict.

Finding a tick is unsettling — but the species you are looking at changes everything about the risk and what you should do next. This hub is the master identification page: use the chart above to narrow it down fast, then follow the links to a detailed close-up guide for each specific tick. Below, we walk through the four features that actually let you tell ticks apart, then hit each common North American species one by one.

The 4 Features That Identify Any Tick

You do not need to be an entomologist. Nearly every backyard tick ID comes down to four things:

  1. Size & life stage. Is it sand-grain small (larva), poppy-seed small (nymph), or sesame-seed sized (adult)? A swollen, bean-like body means it has already fed. See baby ticks, nymphs & seed ticks for the tiny stages.
  2. Body colour. Reddish-orange, chocolate brown, or grey. Blacklegged ticks skew reddish; Dermacentor ticks (dog and wood ticks) are brown.
  3. Scutum markings. The scutum is the hard shield just behind the head. A plain, unmarked scutum points to a blacklegged tick; white or grey marbling points to an American dog or wood tick; a single white dot means a female lone star tick.
  4. Legs & mouthparts. Adults and nymphs have 8 legs; larvae have 6. Blacklegged ticks have distinctly dark (“black”) legs. Lone star ticks have noticeably long mouthparts.

Blacklegged (Deer) Tick — Ixodes scapularis

This is the tick that spreads Lyme disease, and the one to learn best. Adults are small (about 3–4 mm unfed), with a reddish-orange rear half, a solid dark scutum, and uniformly dark legs — hence “blacklegged.” There is no white or ornate patterning on the back. The nymph, active in late spring and summer, is only about the size of a poppy seed and is responsible for the majority of Lyme cases because it goes unnoticed. A blacklegged tick generally needs to be attached for 24 hours or more to transmit Lyme, so prompt removal matters. For a full close-up and range map, see our blacklegged / deer tick guide, and to tell it apart from the look-alike dog tick, our deer tick vs dog tick comparison.

American Dog Tick — Dermacentor variabilis

Larger and easier to spot than the deer tick, the American dog tick has a brown body with distinctive white or greyish marbling on the scutum. Unfed adults are about 5 mm; a fully engorged female can reach 10–15 mm and look like a grey bean. It does not spread Lyme, but it can transmit Rocky Mountain spotted fever and tularemia. This is the tick people most often mistake for a deer tick — the giveaway is the ornate back pattern, which a blacklegged tick never has. Full details in our American dog tick guide.

Lone Star Tick — Amblyomma americanum

Named for the single white dot on the female’s back (males have scattered white streaks instead), the lone star tick is reddish-brown, aggressive, and has notably long mouthparts. Historically a southeastern US tick, its range is expanding northward and it now turns up in the northeastern states and, increasingly, parts of Ontario. It is associated with ehrlichiosis, Southern tick-associated rash illness (STARI), and alpha-gal syndrome — a delayed red-meat allergy triggered by its bite. It does not spread Lyme.

Brown Dog Tick — Rhipicephalus sanguineus

The brown dog tick is unusual: it can complete its entire life cycle indoors, which means infestations in homes, kennels, and dog runs across both the US and Canada. It is a uniform reddish-brown, elongated when unfed, roughly 3 mm, swelling to about 12 mm when engorged, with no clear back pattern and a hexagonal base to the mouthparts. It strongly prefers dogs as hosts but will bite people. In some regions it can transmit Rocky Mountain spotted fever.

Rocky Mountain Wood Tick — Dermacentor andersoni

A western counterpart to the American dog tick, the Rocky Mountain wood tick is brown with a grey/white mottled scutum and is found in the western US and Canada (British Columbia, Alberta, Saskatchewan). Adults are about 5 mm unfed. It can transmit Rocky Mountain spotted fever, Colorado tick fever, and — in rare cases — tick paralysis, a temporary paralysis caused by a toxin in the tick’s saliva that resolves once the tick is removed. Under a hand lens it is hard to separate from the American dog tick; range is the easiest clue.

Not Sure It’s Even a Tick?

Plenty of harmless bugs get mistaken for ticks — from engorged bed bugs and poppy-seed-sized beetles to spider beetles and even clumps of dirt. Legs are the fastest test: ticks have 8 (6 as larvae) and no wings or antennae. If yours has wings, more than 8 legs, or long antennae, it is not a tick. Compare side-by-side in our bugs that look like ticks photo guide, and see the full visual reference in what ticks look like.

If You Found a Tick on You

Regardless of species, act the same way: grip the tick with fine-tipped tweezers as close to the skin as possible and pull straight up with steady, even pressure — no twisting, burning, or smothering with petroleum jelly. Clean the bite, then note the date and, if you can, the species. Keeping a proper removal tool on hand makes this cleaner and reduces the chance of leaving mouthparts behind. Check tick-removal tools on Amazon →

Watch the bite site over the following days and weeks for an expanding erythema migrans (bull’s-eye) rash, fever, aches, or fatigue, and see a doctor if any appear — early treatment is highly effective. For prevention on skin and clothing, EPA- and Health-Canada-registered repellents containing DEET or picaridin, and permethrin applied to clothing and gear, are the evidence-backed choices. Compare permethrin clothing spray →

Explore Each Tick in Detail

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