Do Horse Flies Bite? Are They Dangerous?
Short answer: the horse fly can bite or sting, usually with mild, local effects. Horse fly bites are painful and can swell; they rarely transmit disease to people in the US.
Risk rating: Can bite or sting
Horse fly bites are painful and can swell; they rarely transmit disease to people in the US.
Are horse flies dangerous to humans?
Horse fly bites are painful and can swell; they rarely transmit disease to people in the US.
On our four-level scale, the horse fly is rated can bite or sting, meaning it can bite or sting, usually with mild, local effects. Horse Flies can bite, so it is worth handling them with care.
Are they dangerous to pets?
Horse Flies can bite or sting curious pets that paw at them or try to eat them. Watch for swelling, drooling or limping, and call your veterinarian right away if your pet has trouble breathing or a large reaction.
Can they damage your home or garden?
Horse Flies don't damage homes; the concern is bites outdoors.
What to do if you are bitten
- Wash the area with soap and water.
- Apply a cool compress to reduce swelling.
- Use an over-the-counter antihistamine or hydrocortisone cream for itching, following the label.
- Avoid scratching, which can lead to infection.
Call 911 right away if someone has trouble breathing, swelling of the face or throat, dizziness or a racing heartbeat after a bite or sting.
How to identify horse flies
A large, stout fly with huge eyes that pursues people, horses and cattle for blood. Females slice skin with blade-like mouthparts, causing a sharp, painful bite.
- Large, heavy body with very large, often iridescent eyes
- Clear or dark-tinted wings held apart at rest
- Persistent circling around people near water
| Scientific name | Tabanus spp. |
|---|---|
| Group | Flies & Mosquitoes |
| Size | 10–30 mm (up to about 1.2 in) |
| Colors | Black, Brown and Gray |
| Legs | 6 legs |
| Wings | Yes |
| Where found | Yard or patio, Woods or trails and Near water |
| Most active | Summer |
| Bites | Yes |
| Stings | No |
| Risk level | Can bite or sting |
When you'll see horse flies
Horse Flies are most active in summer. Summer heat speeds up development, so populations can grow quickly.
Typical places to check: yard or patio, woods or trails and near water.
About flies & mosquitoes
The horse fly is one of the flies & mosquitoes. Flies have only one pair of working wings; the second pair is reduced to small balancing knobs called halteres. They go through complete metamorphosis, and the larvae, called maggots, need moist organic material such as garbage, soil, drain film or standing water.
Fly problems are almost always breeding-site problems. Finding and removing the moist material where larvae develop works far better than swatting adults.
How to avoid problems with horse flies
- Wear light-colored long sleeves near ponds and pastures
- Use a repellent on skin and clothing
- Stay in shaded areas, since horse flies prefer sun
Frequently asked questions
Do horse flies bite?
Yes. Horse fly bites are painful and can swell; they rarely transmit disease to people in the US.
Do horse flies sting?
No, horse flies do not sting.
Are horse flies poisonous?
The horse fly can bite or sting, usually with mild, local effects. Horse fly bites are painful and can swell; they rarely transmit disease to people in the US.
Where do horse flies live?
Horse Flies are usually found in yards and on patios, in woods and along trails and near water, and are most active in summer.