They often assemble together in large mating swarms.
All gnats have long, hairlike antennae, which are particularly well-developed in the males.
Gnat larvae are free-living, most feeding on plants. Larval plant feeders, e.g., the Hessian fly larvae, cause root, stem, and leaf galls to be formed by the host plant. Gnats are classified in the phylum Arthropoda , class Insecta, order Diptera.