When do insect bites peak in Canada?
Across 77,025 verified records for Canada, biting and stinging activity concentrates in May to September — August alone accounts for 22% of sightings, and December is the quietest month of the year.
The year, month by month
| Month | Activity | Share | Mostly |
|---|---|---|---|
| January | 0% | Bed bug, Scabies, Head lice bites | |
| February | 0% | Bed bug, Scabies, Head lice bites | |
| March | 2% | Honey bee, Bed bug, Flea | |
| April | 6% | Honey bee, Carpenter ant, American dog tick | |
| May | 11% | Honey bee, Paper wasp, Carpenter ant | |
| June | 14% | Honey bee, Bald-faced hornet, Paper wasp | |
| July | 19% | Honey bee, Bald-faced hornet, Paper wasp | |
| August | 22% | Honey bee, Bald-faced hornet, Paper wasp | |
| September | 19% | Honey bee, Bald-faced hornet, Paper wasp | |
| October | 6% | Honey bee, Bald-faced hornet, Yellowjacket | |
| November | 1% | Yellow sac spider, Bed bug, Flea | |
| December | 0% | Bed bug, Scabies, Head lice bites |
Calculated from GBIF biodiversity records for Canada, snapshot 2026-07-27. Records reflect when people observe and report specimens, which tracks activity closely but is not the same as how often anyone gets bitten. See our methodology.
What actually bites you in Canada
Canada has the shortest and most concentrated bite season of any country here — in much of the country it runs from late May to early September, and blackfly and mosquito pressure during those weeks can be extreme by any standard. The medically important change over the past two decades is northward: blacklegged ticks and Lyme disease have become established in southern Ontario, Quebec, the Maritimes and parts of Manitoba, in areas where they were previously absent.
| Species | Pattern | Where on body | Records | Peak here |
|---|---|---|---|---|
| Honey bee sting | single | feet — bees are often stepped on in clover, hands | 37,044 | June to September |
| Bald-faced hornet sting | often several — the colony defends aggressively | head, neck | 11,312 | July to September |
| Paper wasp sting | usually single | hands, head | 9,039 | July to September |
| Carpenter ant bite | single or a few | hands, arms | 4,579 | May to July |
| Yellowjacket sting | single or several — this wasp can sting repeatedly | hands, face | 4,531 | August to October |
| American dog tick bite | single | scalp, neck | 3,382 | May to July |
| Deer tick bite | single, usually in a skin fold or hairline | groin, armpits | 3,232 | April, May, June, October |
| Yellow sac spider bite | single, sometimes two nearby | neck, arms | 1,562 | September |
| Horsefly bite | single, occasionally two | legs, back | 513 | June to August |
| Mosquito bite | single bumps scattered over exposed skin | ankles, lower legs | 489 | June to August |
| Black fly bite | several, along the hairline, ears and ankles | hairline, behind the ears | 406 | June to August |
| Bed bug bite | lines or zigzags of three or more — the classic "breakfast, lunch and dinner" | arms, shoulders | 321 | November |
| Flea bite | clusters of three or four, or short irregular groups | ankles, shins | 213 | July to August |
| Deer fly bite | single or a few, often on the scalp and neck | scalp, neck | 192 | June to July |
Honey bees usually top records like these because they are the most photographed insect on earth, not because they sting most often. Read the column as "definitely present here", not as a ranking of risk.
What is different about Canada
Short, intense season. Lyme risk is expanding north and is now a real consideration in the southern provinces rather than a US-only issue.
Species linked to illness here
- American dog tick bite — Rocky Mountain spotted fever, tularemia, tick paralysis (rare, resolves on removal)
- Deer tick bite — Lyme disease, anaplasmosis, babesiosis, Powassan virus (rare)
- Mosquito bite — West Nile virus, La Crosse encephalitis, dengue (Gulf Coast and Southwest, local cases), chikungunya (rare, travel-linked)
- Flea bite — murine typhus (Gulf Coast, California, Hawaii), cat scratch disease bacteria carried between cats, flea tapeworm (mainly in children who swallow a flea)
- Deer fly bite — tularemia (rare)
- Scabies rash — secondary bacterial skin infection is common from scratching
Most bites transmit nothing. What matters is the follow-up: note the date, and report any fever or expanding rash in the weeks afterwards to a clinician, mentioning the bite and where you were.
Stings rather than bites
Honey bee, Bald-faced hornet, Paper wasp, Carpenter ant, Yellowjacket are recorded in Canada. Stings differ from bites in one way that matters: they can cause anaphylaxis in sensitised people, and that risk does not depend on how mild previous stings looked. Anyone who has had a severe reaction should carry an adrenaline auto-injector.
Year-round regardless of season
Weather does not affect everything. Bed bugs, scabies and head lice depend on people rather than temperature, so a bite pattern in the middle of Canada's quiet season points to those first — see what is biting me at night.
Seek medical care if
Call emergency services now for difficulty breathing, swelling of the lips, tongue or throat, dizziness or fainting, or hives spreading away from the bite.
- difficulty breathing, or swelling of the lips, tongue or throat after a sting
- a red area that is spreading, hot and painful, especially with a red streak
- fever, chills or feeling generally unwell in the days or weeks after a bite
- an expanding rash appearing 3 to 30 days after a tick bite
- a bite that is getting worse rather than better after 72 hours
Where to get help in Canada
Call 911 for emergencies. Provincial telehealth lines (811 in most provinces) give nurse advice without a visit.
Get a photo assessment in the app
Everything above is free to read. The app adds what a page cannot: point your camera at the bite and get an assessment of the most likely cause, a severity read, and a day-by-day care plan — including the specific signs that mean you should be seen.
iPhone and iPad. Free to download.