Gnats eat algae, fungus and various plants. Unlike mosquitoes, they do not consume blood. Some gnats do not eat during their three- to four-week lifespan.
Gnats are a food source for bats, birds and other insects. Gnats help out in nature by pollinating plants. There are many other small insects that are often mistaken for the gnat, including the fruit fly.
Gnat larvae hatch from eggs, and moist soil is their breeding ground. To avoid a gnat infestation, soil that has been sitting outdoors should remain outdoors. If a gnat infestation occurs in a potted plant, the soil should be left to dry out for a few days.