Adult gnats, also known as midges, live for approximately three to five days, following an incubation period of three to seven weeks as larvae and approximately three to five days in the pupa stage. Five generations of gnats can spawn within one summer.
Gnats gestate in water and have four distinct development stages: egg, larvae, pupa and adult. Shortly after pupating, gnats mate and discontinue eating, which contributes to the short adult lifespan.
Gnats are common insects that thrive in watery environments, such as natural lakes, sewage processing plants and slow-moving rivers, and it's not uncommon to observe as many as 4,000 insects per square yard of water materialize in one evening. Gnats are often mistaken for mosquitoes, but they don't bite.