TickPrevention.org · updated November 2026
Everything you need to know about ticks in one place: the species, the diseases they carry, how to find and remove them, how to get one tested, where they live, how communities control them, and what to put on your skin and clothes.
Blacklegged tick, actual relative size
Nymphs, about the size of a poppy seed, cause most human infections because they are so hard to spot.
About 90 tick species live in the United States, but a handful do almost all the biting. Ticks are arachnids, related to spiders and mites. Hard ticks (most below) feed for days; soft ticks feed for minutes, usually at night.
Ixodes scapularis
Ixodes pacificus
Amblyomma americanum
Dermacentor variabilis
Dermacentor andersoni
Rhipicephalus sanguineus
Amblyomma maculatum
Haemaphysalis longicornis
Ixodes cookei
Ornithodoros species
Most tick bites cause nothing more than a small red bump. But one tick can carry several germs at once, and some infections become serious if treatment is delayed. Many early symptoms look like the flu, so tell your doctor about any tick bite or time spent outdoors.
| Illness | Spread by | Symptoms start | What to watch for | Severity |
|---|---|---|---|---|
| Lyme diseaseBorrelia bacteria | Blacklegged, western blacklegged | 3–30 days | Expanding "bull's-eye" or solid red rash (about 70–80% of cases), fever, chills, fatigue, joint aches. Untreated: arthritis, facial palsy, heart rhythm problems, nerve pain | Serious if untreated |
| Anaplasmosis | Blacklegged | 5–14 days | Fever, severe headache, chills, muscle aches; low blood counts on labs | Can be severe |
| BabesiosisParasite of red blood cells | Blacklegged | 1–4 weeks or longer | Fever, sweats, fatigue, dark urine from anemia. Dangerous for people without a spleen, older adults, the immunocompromised. Also spread by blood transfusion | Can be fatal |
| Powassan virus | Blacklegged, groundhog | 1 week–1 month | Fever, vomiting, confusion, seizures, brain inflammation. Can transmit in as little as 15 minutes. No specific treatment | About 1 in 10 severe cases fatal |
| Ehrlichiosis | Lone star | 1–2 weeks | Fever, headache, muscle pain, confusion; rash more common in children | Can be fatal |
| Rocky Mountain spotted fever | Dog tick, wood tick, brown dog tick | 3–12 days | Fever and headache first, then a spotted rash on wrists and ankles around day 2–4. Treat within 5 days of symptoms | Most deadly U.S. tick disease |
| Alpha-gal syndrome | Lone star (mainly) | Reaction 2–6 hours after eating | Hives, stomach pain, swelling or anaphylaxis after red meat, dairy or gelatin. CDC estimates up to 450,000 Americans affected | Can be lifelong |
| Tularemia | Dog tick, wood tick, lone star | 3–5 days | Skin ulcer at the bite, swollen lymph nodes, high fever | Treatable |
| STARI | Lone star | About 7 days | Lyme-like circular rash, fatigue, fever | Usually mild |
| Borrelia miyamotoi | Blacklegged | 1–2 weeks | High fever that can come back; rash uncommon | Treatable |
| Rickettsia parkeri | Gulf Coast | 2–10 days | Dark scab (eschar) at the bite, fever, rash | Treatable |
| Heartland & Bourbon viruses | Lone star | About 2 weeks | Fever, fatigue, low platelets and white cells. Rare; no specific treatment | Can be severe |
| Colorado tick fever | Rocky Mountain wood tick | 1–14 days | Fever that breaks and returns, headache, body aches | Usually recovers |
| Tick-borne relapsing fever | Soft ticks | About 7 days | Repeated 3-day fevers separated by about a week | Treatable |
| Tick paralysis | Dog tick, wood tick | After 4–7 days attached | Weakness spreading up from the legs. A toxin in tick saliva, not an infection: it reverses once the tick is found and removed | Find the tick |
How long a tick must be attached matters. Lyme usually needs 36–48 hours, which is why daily checks work. Anaplasmosis and spotted fever can pass in hours, and Powassan in minutes.
Ticks can't jump or fly. They wait on low plants with front legs stretched out ("questing") and grab whatever brushes past. Then they crawl upward, often for hours, looking for thin, warm, hidden skin.
Do it every day you've been outdoors in tick country, within two hours of coming inside. Use a hand mirror or a partner for places you can't see.
Dogs get Lyme, ehrlichiosis and anaplasmosis, and they carry ticks into beds and couches. Ask your vet about an oral or topical tick preventive and the canine Lyme vaccine. Cats can get other tick diseases. Never use dog products containing permethrin on cats; it is toxic to them.
The right way to pull a tick, what never to do, what to save, and how to get the tick and yourself tested.
Read the removal guide → Skin, clothing & natural oilsDEET, picaridin, permethrin and the rest compared, plus which natural oils repel ticks and how to use them safely.
Read the repellent guide →No agency counts ticks the way it counts people. "Tick population" is measured indirectly, through field drags, range maps and human case reports. This table combines CDC range maps and reported cases into an approximate risk level. Ranges are expanding north and west every year, driven by milder winters, growing deer populations and suburban woodland.
| State | Region | Main biting ticks | Risk | Notes |
|---|
Brown dog ticks occur in every state. Asian longhorned tick is marked only where detections have been widely reported; it was in 27 states as of July 2026. Risk levels are approximate and vary greatly within a state.
| Place | Year | Lyme cases | Trend |
|---|---|---|---|
| Massachusetts | 2025 | 8,619 probable | Barnstable County (Cape Cod) rate about 3× state average |
| Maine | 2025 | 4,257 | Up about 32% from 3,218 in 2024; anaplasmosis also a record 1,604 |
| Michigan | 2025 | ~3,400 | Up from under 2,300 in each of the prior three years |
| United States | 2023 | 89,000+ reported | CDC estimates ~476,000 diagnosed and treated per year |
Blacklegged ticks have spread north across southern Ontario, Quebec, Nova Scotia and Manitoba; Lyme cases have risen sharply over the past decade.
The castor bean tick (Ixodes ricinus) spreads Lyme and tick-borne encephalitis (TBE). Central Europe, Scandinavia and the Baltics are hotspots. A TBE vaccine exists for travelers.
Taiga tick (Ixodes persulcatus) spreads TBE and Lyme. Crimean-Congo hemorrhagic fever from Hyalomma ticks in Turkey, the Balkans and Central Asia.
Asian longhorned tick spreads SFTS virus in China, Japan and Korea, which can be deadly. Japanese spotted fever also occurs.
The paralysis tick (Ixodes holocyclus) on the east coast can paralyze pets and people and is linked to mammalian meat allergy.
African tick-bite fever in southern Africa (common in safari travelers). Brazilian spotted fever and Mexican spotted fever from Amblyomma and brown dog ticks.
Experts call it integrated tick management: no single method works alone, so properties and towns stack several. Results below come from field studies; real-world numbers vary.
Cheapest, every yard
Clear leaf litter, mow short, cut back brush, stack wood neatly in the sun, and put a 3-foot border of wood chips or gravel between lawn and woods. Keep play sets, patios and gardens away from tree lines.
Often 80–90%+ for a season
Licensed applicators spray synthetic acaricides (such as bifenthrin or permethrin) on woods edges, stone walls and shrubs, usually in late spring and again in fall. Effective, but also kills pollinators and other insects. Ask about targeted, low-volume application.
Lower-toxicity option
Metarhizium fungi (sold as Met52 and similar) infect and kill ticks. EPA-registered. Works best combined with bait boxes; less effective in hot, dry weather.
About 79–84% fewer nymphs
Mice enter a station and get a dab of fipronil (the same ingredient in many dog tick treatments), killing larvae and nymphs before they become infected. Usually placed by professionals.
About 20–28% control in studies
Cardboard tubes of permethrin-treated cotton that mice carry into nests. Easy and cheap, but much weaker than bait boxes in head-to-head comparisons.
At least 77% community control
Developed by USDA. Deer eat corn and rub against rollers coated with acaricide. Requires permits, corn, and attention to local deer feeding rules. Used on islands and gated communities.
Works only at very low density
Adult ticks rely on deer. Studies show deer must be cut below about 5 per square kilometer to lower tick numbers, which is hard to reach. An 8-foot deer fence protects a single property.
Experimental
Oral bait vaccines for white-footed mice aim to stop Lyme bacteria in the animals that infect ticks. Being tested in the Northeast.
Pfizer and Valneva's vaccine (PF-07307405, formerly VLA15) showed 73.2% efficacy in its 9,437-person Phase 3 trial, announced March 2026. The European Medicines Agency accepted it for review in August 2026. It is not yet approved anywhere, and it would not protect against other tick diseases. The schedule is three doses in year one plus a booster.
Cost of doing it as a town: a 2023 study of a model 1,000-home New Jersey community estimated $373–$439 per household per year for spraying plus 4-Posters, rising to over $3,000 per household when bait boxes were added.
TickPrevention.org is for education and general awareness. It isn't medical advice and doesn't replace care from a clinician. Product and pathogen information follows CDC, EPA and university extension guidance as of November 2026.