Gnat Fly


Actual Size: 1⁄16” to ⅛”

Characteristics: Grayish-black with gray or see-through wings.


  • Their presence in an area will attract spiders.
  • Also known as midges, they fly in swarms that look like clouds.
  • Often mistaken for mosquitoes, but do not bite or spread disease.


Gnats and midges are common names for a large number of small, non-biting flies found throughout the United States. These flies typically breed in aquatic environments and can emerge from these sources in high numbers. Most species that affect homes and buildings are nighttime fliers that are attracted to the light on buildings. People are often troubled by the presence of these insects as they confuse them with mosquitoes. However, unlike mosquitoes, midges and gnats lack a biting needle, and because of this, they cannot spread disease.

Gnat Habitat

Gnats and midges are most common in spring and summer and are important pests around lakes, rivers, and aquatic areas where they lay their eggs. Although they are weak fliers, they can be carried long distances by downwind, migrating from nearby ponds, lakes, or rivers to swimming pools, homes and buildings. Many gnats and midges are attracted to light and maybe a nuisance, landing on people or entering homes or businesses. These tiny flies do not feed and only live long enough to mate, lay eggs, and die.

Gnat Behavior – Threats – Dangers

Although they do not bite, during peak emergence, immense numbers of gnats and midges move into adjacent residential or industrial areas causing annoyance and damage. Lake-front homes, sporting facilities, recreational areas, and businesses are often blanketed by these insects Midges and gnats fly in swarms that look like clouds and can completely cover houses, vehicles, patio furniture, and plants in the landscape. Where midges are plentiful, spiders, and spider webs abound, and this adds to people’s concern. At night, midges are attracted to outdoor lights in large numbers.

Gnat Prevention

To deter gnats and midges, eliminate items around the home that retain water such as buckets, empty flower pots, tires, jars, bottles, and play equipment. Install small-mesh screens in windows to prevent their entry. Reduce or eliminate outdoor lighting, or change out bulbs to low voltage, yellow bug lights. Repair leaky pipes and outdoor faucets and empty and clean kiddie pools at least once a week. Empty and refill pet water containers daily and cover garbage and trash bins to prevent water accumulation.