The common name for the several small insects belonging to the insect Order Diptera Suborder Nematocera is gnat. The Suborder Nematocera contains the notable insect Family Chironomidae and Culicidae as well as some of the primitive insects of Order Diptera. Non-biting midges belong to the Family Chironomidae while mosquitoes belong to the insect Family Culicidae.

Insect Families that are belong in this Suborder include the Ceratopogonidae (biting midges), Tipulidae (crane flies), Cecidomyidae (gall midges), Simuliidae (black flies), Bibionidae (hairflies) and more.

When you hear the terms vinegar flies and fruit flies, they also refer to gnats. These names were derived from the fact that gnats are usually drawn to the smell of rotten food. The usual location for these insects include saturated house plants, drains, fruits, rotting, smelly foods such as the compost piles and garbage. They move in groups or swarms and it is very unlikely that you can find only one gnat flying around.

There's a big possibility that gnats are egg-laying inside your home when you see them flit around trash cans and/or drains. Up to three hundred eggs can be laid by a single gnat in their life span (2-4 months). When the eggs hatch, they become larvae. The larvae of gnats feed on plants and/or animals. They are mostly free-living.

The gnat larva have beneficial effects. The gnat larva that feed on plants (larva of Hessian fly) causes parts of a plant like the stem, root and leaf galls to be developed by the plant they are feeding on. Gnats also help in pollinating plants like for example in the South American Pleurothallid orchid. This orchid have tiny flowers because the pollinators were also tiny (gnats). Not all gnats are beneficial, however. The insect Family Sciaridae and Mycetophilidae are fungus gnats that are considered pests because they damage roots of potted plants and mushrooms.