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July 30, 2026Short & citedBlog
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Field Notes • Insect

Gnat

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

Updated July 30, 20261 min readCited sources

A gnat is a common name for many kinds of very small flying insects, especially small flies. The term is broad and includes both biting and non-biting species.

What it is

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. All gnats belong to the insect order Diptera, the true flies. They are typically very small, with slender bodies, long antennae, long legs, and one pair of wings.

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. Many are weak fliers. In Canada, they are often noticed indoors or outdoors near moisture.

Common types

The name gnat may refer to fungus gnats, biting midges, black flies, fruit flies, or other small flies depending on local usage. Some are non-biting nuisance species, while others bite humans or animals. Orkin Canada notes more than 600 gnat species in North America.

In short

  • Gnat is a broad common name, not a single species or family.
  • Gnats belong to the order Diptera (true flies).
  • Some gnats bite; others are non-biting nuisances.
  • Over 600 species exist in North America.
Canadian angle

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]

Quick 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.
Do all gnats bite?
No. Some are biting species, while others are non-biting and mainly nuisance insects.
Why do gnats swarm?
Some species swarm, especially at dusk, as part of mating behavior.

Sources

  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.