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Gnat Control: Protect Your Home or Business


  • While they are actually different species, people often refer to any small flying insect as a gnat. Fungus gnats, biting midges, and fruit flies are usually part of this group.
  • While the pests do have wings, most are weak fliers that move in a zig-zag pattern close to the ground.
  • Adult gnats and larvae can spread fungal plant diseases with their droppings.


Gnat species are difficult to tell apart due to their size. Fungus and biting gnats are no bigger than a grain of rice and have black or gray bodies with long legs. They both have segmented antennae and transparent wings. Gnat larvae are white with a distinctive dark, shiny head. Their bodies are about a quarter-inch in length.

While similar in size, fruit flies are yellow or brown with black abdominal stripes. The easiest way to identify the pests is by their red compound eyes. Cream-colored fruit fly larvae typically inhabit overripe produce, making them hard to spot until you cut up or bite into the vegetables.

How Do Gnats Get Inside Buildings?

Fungus gnats often end up inside homes accidentally. Plants brought in from the outside can harbor gnat eggs, larvae, and pupae, leading to infestation. Other species such as biting midges, or no-see-ums, tend to stay outdoors, but they can get into a residence through window screens, holes in foundations, and gaps under doors.

Outdoor farmer’s markets, greenhouses, and garden centers provide gnats with easy access to food. Fruit flies may enter grocery stores through open loading bays during shipments, which can affect consumer products. Gnats also infest decorative plants in offices and schools, laying eggs in the soil and increasing their population.

Signs of Gnat Infestation

  • Bites – Small welts coupled with skin irritation could be the result of biting gnats.
  • Larvae – If an infestation is severe, you may notice gnat larvae crawling on the soil in planters.
  • Pests around Lights – Swarms of adult gnats seek out light in the form of restaurant signs, computer screens, and well-lit workshops.

Problems Caused by Gnats

Gnats are mostly harmless, but the pests are a nuisance inside a house or an apartment. Fungus gnat larvae cause issues in gardens, while fruit flies affect the quality of homegrown vegetables. On the other hand, when biting midges take blood meals, itchy, painful welts appear on both people and animals.

In the hospitality trade and inside commercial kitchens, gnats can be a serious issue. For example, bed and breakfast hosts and hotels may see a sharp increase in bad reviews if fungus gnats swarm a guest’s room or potted plants in lobbies. In addition, fruit flies may lay eggs in overripe produce, creating a health hazard in restaurants as well as school and office cafeterias.

Prevention Tips

Repair torn screens or replace them with insect-proof mesh to prevent gnats from getting inside a home or business. Sealing foundation cracks is a good idea, too. Since gnats like moisture, avoid overwatering plants or leaving stagnant water in sinks. Contact Western Pest Services and talk to a technician if you have a gnat problem.

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