Pest profile

Eye Gnats

Liohippelates collusor and Hippelates species · Diptera: Chloropidae[2]

Female eye gnats persistently feed at the eyes, nose, mouth and open wounds of people and animals, a severe nuisance near breeding sites.[1]

Eye gnat, a tiny dark gray fly with red eyes and orange-brown legs, on a white surface
Eye gnat, a tiny dark gray fly with red eyes and orange-brown legs, on a white surface. (c) Tom, some rights reserved (CC BY) — via iNaturalist, CC BY 4.0

How to identify it

  • Eye gnats are small flies, 1/16 to 1/8 inch, with shiny black or gray bodies and yellow to orange-brown legs.[1]
  • Their persistent attraction to eyes and wounds sets them apart from other small flies.[1]

Look-alikes

Look-alikeHow to tell them apart
Fungus gnatsFungus gnats aren't attracted to eyes the way eye gnats are.[1]
Biting midges (no-see-ums)Midges can bite and draw blood; eye gnats can't make wounds.[1]
Black fliesBlack flies bite; eye gnats only sponge up secretions.[1]

Where it lives

Liohippelates collusor is the most abundant species in California and also occurs in the Southwest and northern Mexico.[1]

US map: state the cited source covers (the main species also occurs in parts of the southwest).

Biology and life cycle

They breed in moist, well-drained sandy soil rich in organic matter, and the wind can carry them miles from breeding sites.[1]

The life cycle averages about 28 days; activity peaks between 70 and 90 degrees F.[1]

Damage and signs

  • Swarms can discourage outdoor recreation near farms, schools, parks and golf courses.[1]

Health risk

Eye gnats don't bite, but they feed on secretions at the eyes and wounds and can potentially spread disease-causing organisms.[1]

Control

Prevention

Turn less fresh organic matter into soil and flowerbeds, and reduce surface moisture, which cuts egg laying.[1]

Keep them out

Screen fences about 8 feet high kept out more than 90 percent of eye gnats in research, since they fly low.[1]

Traps and physical control

Egg-baited bottle traps, refreshed at least every 14 days, give some relief when combined with repellents.[1]

Pesticides

For temporary relief, repellents with DEET or picaridin help; insecticides are rarely if ever warranted around homes.[1]

Common questions

Why do tiny flies keep going for my eyes?
They're likely eye gnats; females feed on eye secretions and are very persistent.[1]
Do eye gnats bite?
No; they can't pierce skin, but they soak up secretions with sponge-like mouthparts.[1]

Sources

  1. University of California Statewide IPM Program, “Eye Gnats (Pest Notes).” ipm.ucanr.edu/home-and-landscape/eye-gnats/ (accessed 2026-10-06)
  2. iNaturalist, “Liohippelates collusor taxon page (order and family).” www.inaturalist.org/taxa/1628486 (accessed 2026-10-06)

Updated 2026-10-14. Built from sourced records. Spot an error? Tell us.