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Gnat

A gnat is a common name for several kinds of very small flying insects, especially small flies.

By Ethan Anderson| Reviewed by Olivia Bennett, Standards & Fact-Checking Lead| Updated July 26, 2026|2 min read| Fact-checked

A gnat is a common name for several kinds of very small flying insects, especially small flies. In everyday use, the term is broad and not a single scientific classification; it may refer to biting or non-biting insects in different fly groups. Gnats are often nuisance insects and are commonly associated with swarms, moisture, plants, or decaying organic matter.

Taxonomy and usage

Gnat is a loose common name, not a formal scientific taxon. Different regions use it for different small flies, including biting and non-biting types.

Physical characteristics

Gnats are typically very small insects with slender bodies, long antennae, long legs, and one pair of wings. Their appearance often leads to confusion with mosquitoes and other small flies.

Habitat and behavior

Gnats are commonly associated with damp environments, houseplants, soil, fungi, and decaying organic matter. Some species form swarms, often at dusk, especially during mating.

Types commonly called gnats

The name may refer to fungus gnats, biting midges, black flies, fruit flies, or other small flies depending on local usage. In some contexts, the insects are non-biting nuisance species, while in others they bite humans or animals.

Key facts

  • The word gnat is a broad common name for many tiny flies rather than one species or family.
  • Gnats belong to the insect order Diptera, the true flies.
  • Many gnats are small, long-legged, and weak fliers.
  • Some gnat-like insects are biting, while others are non-biting.
  • Gnats are often noticed near moisture, plants, soil, fungi, or decaying organic material.
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Canadian context

In Canada, 'gnat' is used as a broad common name for several small flies, and Canadian readers may encounter them indoors, around plants, or outdoors near damp areas. Orkin Canada notes that there are more than 600 gnat species in North America.[1]

Frequently asked questions

What is a gnat?
A gnat is a common name for several kinds of very small flying insects, especially small flies. It is not a single scientific group.
Are gnats flies?
Yes. Gnats are insects in the fly order Diptera.
Do all gnats bite?
No. Some are biting species, while others are non-biting and mainly nuisance insects.
Where are gnats commonly found?
Gnats are often found near moisture, soil, fungi, houseplants, and decaying organic material.
Why do gnats swarm?
Some species swarm, especially at dusk, as part of mating behavior.
Are gnats a single species?
No. The term refers to many different small flies, depending on region and context.

References

  1. Orkin Canadahttps://www.orkincanada.ca/pests/flies/gnats/
    Supports: Size, morphology, and statement that there are more than 600 species of gnat in North America.
  2. WebMDhttps://www.webmd.com/a-to-z-guides/gnats-what-to-know
    Supports: Gnats as tiny winged flies in Diptera and general description as nuisance insects.
  3. Encyclopaedia Britannicahttps://www.britannica.com/animal/gnat
    Supports: Gnat as a common name for several small flies and regional usage variations.
  4. University of Kentucky Entomologyhttps://entomology.mgcafe.uky.edu/ef632
    Supports: Gnats and midges as common names for small flies; not a single insect family.
  5. Holders Pest Solutionshttps://www.holderspestsolutions.com/pest-library/flying-insects/gnats/
    Supports: Size, weak-flying behavior, swarm at dusk, biting vs non-biting species, and feeding habits.
  6. Orkinhttps://www.orkin.com/pests/flies/gnats
    Supports: Gnats as small long-legged insects, common name for many small winged insects, and not necessarily 'babies'.
  7. Clemson Home & Garden Information Centerhttps://www.clemson.edu/extension/hgic/pests/gnats.html
    Supports: Different small flies referred to as gnats and distinction between biting gnats and non-biting types.