Bald-faced hornet bites in Idaho

Idaho has 515 verified bald-faced hornet records in the GBIF biodiversity database — ranking it 19th nationally. Sightings concentrate in June to September. The bite itself appears immediate severe pain and lasts swelling for several days.

Bald-faced hornet in Idaho — semi-arid climate
Verified records515
Peak sightingsJune to September
State bite seasonMay to September
Activedaytime
Habitatenclosed grey paper nests the size of a football, hanging in trees, on sheds and under eaves
Bite appearsimmediate severe pain

Identifying it in Idaho

Technically a large yellowjacket, black with an ivory-white face, and the most defensive of the group. Multiple stings during a single encounter are typical because the colony responds together and follows for a distance.

Locally, the species most often confused with it are mosquito bite, honey bee sting, paper wasp sting — all of which are also recorded in Idaho.

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.

  • breathing difficulty, throat tightness, faintness, hives away from the site
  • multiple stings
  • stings to the face or mouth

What else it could be in Idaho

These are recorded in Idaho too and are the ones most often confused with it here. The differences below are the ones that actually separate them.

Bald-faced hornet stingPaper wasp stingYellowjacket sting
Patternoften several — the colony defends aggressively usually singlesingle or several — this wasp can sting repeatedly
Where on bodyhead, neck, arms hands, head, arms — often while gardening or opening a shutterhands, face, neck
Appearsimmediate severe pain immediate sharp painimmediate sharp pain
Records here515 1,01573

Season in Idaho specifically

Records in Idaho concentrate in June to September, which is what local sighting data shows rather than a national average — seasonality shifts substantially with latitude. The general bite season in Idaho runs May to September.

Because enclosed grey paper nests the size of a football, hanging in trees, on sheds and under eaves, exposure in Idaho tends to be concentrated in specific places rather than spread evenly — which is why a bite history ("where were you in the 24 hours before?") narrows the answer faster than the appearance of the mark.

Care

  1. leave the area quickly — this species pursues
  2. cold pack, antihistamine, pain relief
  3. adrenaline auto-injector if prescribed

Avoiding them in Idaho

Questions

When are bald-faced hornets active in Idaho?

Idaho records peak in June to September. The general bite season in Idaho runs May to September.

Are they common in Idaho?

Idaho accounts for 515 verified records in GBIF, ranking it 19th among states for this species. Records reflect reporting effort as well as abundance.

What does the bite look like?

a large, hot, red swelling with a central point, red. Often several — the colony defends aggressively.

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.

Download for iPhone — free

iPhone and iPad. Free to download.