| 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 |
How to identify it
The horse fly is a medium-sized member of the flies & mosquitoes group. Only one pair of flying wings; the hind pair is reduced to tiny knobs. Check for these three features:
- Large, heavy body with very large, often iridescent eyes
- Clear or dark-tinted wings held apart at rest
- Persistent circling around people near water
About this bug
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.
You'll usually find horse flies in yards and on patios, in woods and along trails and near water. They are most active in summer.
Is it dangerous?
Horse fly bites are painful and can swell; they rarely transmit disease to people in the US.
Our rating: Can bite or sting, meaning it can bite or sting, usually with mild, local effects.
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.
What to do about it
- 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
Read the full guide: how to get rid of horse flies.
Bugs that look similar
Size: Horse Flies are larger, reaching 30 mm, while house flies top out around 7 mm.
Size: Horse Flies are larger, reaching 30 mm, while blow flies top out around 12 mm.
Frequently asked questions
What does a horse fly look like?
Large, heavy body with very large, often iridescent eyes. Adults measure 10–30 mm (up to about 1.2 in).
Does the horse fly bite or sting?
It can bite. It does not sting. Horse fly bites are painful and can swell; they rarely transmit disease to people in the US.
Where do horse flies live?
Horse Flies live in yards and on patios, in woods and along trails and near water.
When are horse flies most active?
Mostly in summer.