What bit me in Indiana?

19 biting or stinging species have verified records in Indiana. The fastest way to narrow it down is where on your body the marks are and how they are arranged — below the knee in clusters points to fleas or chiggers, lines on uncovered skin point to bed bugs, scattered single bumps point to mosquitoes. Bite season here runs roughly April to October.

Active around now in Indiana

Recorded biting species in Indiana

SpeciesLooks likeWhere on bodyRecordsPeak
Mosquito bite single bumps scattered over exposed skin ankles, lower legs 18,248 June to September
Honey bee sting single feet — bees are often stepped on in clover, hands 2,922 May, June, July, September
Bald-faced hornet sting often several — the colony defends aggressively head, neck 843 July to October
Carpenter ant bite single or a few hands, arms 622 April, May, June, September
Paper wasp sting usually single hands, head 512 June to September
Deer fly bite single or a few, often on the scalp and neck scalp, neck 419 June to July
American dog tick bite single scalp, neck 388 April to July
Yellowjacket sting single or several — this wasp can sting repeatedly hands, face 266 September to October
Lone star tick bite single, sometimes dozens at once when larval "seed ticks" swarm legs, waist 185 April to June
Brown recluse spider bite single site torso under clothing, upper arms 183 May to August
Scabies rash symmetrical, in finger webs, wrists, waistline, armpits and groin finger webs, wrists 90 July
Deer tick bite single, usually in a skin fold or hairline groin, armpits 63 March, April, October, November
Horsefly bite single, occasionally two legs, back 51 June to August
Bed bug bite lines or zigzags of three or more — the classic "breakfast, lunch and dinner" arms, shoulders 36 May, June, September
Kissing bug bite clusters, often on the face near the lips or eyes face, lips 33 June to August
Yellow sac spider bite single, sometimes two nearby neck, arms 30 April, May, June, October
Flea bite clusters of three or four, or short irregular groups ankles, shins 24 June, August, September, October
Chigger bite clusters concentrated where clothing is tight ankles, behind the knees 7 May, July, August, September
Black widow spider bite single site hands, forearms 3 June, July, September, October

Record counts come from the GBIF biodiversity database and reflect how often a species is reported and identified in Indiana. They are a guide to what is plausible here, not a census — and they say nothing about how likely you are to be bitten indoors.

Bite season month by month

Of the 19 species recorded in Indiana, 19 are active in June — the peak of the local season. The humid continental climate here is what sets those boundaries: species that need warmth disappear at the edges of the year, while the indoor ones do not care.

MonthSpecies activeNotably
January 2 Scabies, Bed bug
February 2 Scabies, Bed bug
March 5 Honey bee, Lone star tick, Scabies
April 12 Mosquito, Honey bee, Carpenter ant
May 17 Mosquito, Honey bee, Carpenter ant
June 19 Mosquito, Honey bee, Bald-faced hornet
July 19 Mosquito, Honey bee, Bald-faced hornet
August 19 Mosquito, Honey bee, Bald-faced hornet
September 17 Mosquito, Honey bee, Bald-faced hornet
October 12 Mosquito, Honey bee, Bald-faced hornet
November 4 Scabies, Bed bug, Yellow sac spider
December 2 Scabies, Bed bug

Narrowing it down in three questions

  1. Where on your body? Below the knee in clusters points to fleas or chiggers. Uncovered skin — arms, shoulders, neck — points to bed bugs or mosquitoes. Along a sock line or waistband is close to diagnostic for chiggers.
  2. How are they arranged? A line or zigzag of three or more suggests bed bugs. Scattered single bumps suggest mosquitoes. A curved group with white pustules the next day means fire ants.
  3. Indoors or outdoors, and when? Bites that appear overnight in one specific bed are a different problem from bites after an afternoon in tall grass. In Indiana the outdoor season runs April to October; the indoor species run all year.

Stings rather than bites in Indiana

Honey bee, Bald-faced hornet, Carpenter ant, Paper wasp, Yellowjacket are recorded here. Stings differ from bites in one way that matters: they can cause anaphylaxis in sensitised people, and that risk does not depend on how bad previous stings looked. Anyone who has had a severe reaction should carry an adrenaline auto-injector.

Species associated with illness here

Most bites from these species transmit nothing. What matters is the follow-up: note the date of the bite, and report any fever or expanding rash in the following weeks to a clinician, mentioning the bite explicitly.

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

Year-round in Indiana

Weather does not affect everything. Bed bugs, scabies and head lice depend on people rather than season, so a bite pattern in January in Indiana points to those first — see what is biting me at night.

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.