Found this info. online: I'll see what else I can find. "Buffalo gnats are small, humpbacked flies," says Phil Glogoza, entomologist for the North Dakota State University Extension Service. "They can be a major nuisance due to their buzzing presence and constant crawling, not to mention their irritating bite. Their tendency to bite increases toward sunset, but they don't bite after dark, and they seldom attack indoors, or even in a vehicle." Buffalo gnats may be more numerous near rivers and streams, since that's where the larvae develop. But they can be blown long distances. The best defense for people: clothing. "They don't bite through clothing," says Glogoza, "but do have a knack for crawling into hair and under clothing. Tucking trouser cuffs into socks prevents them from getting at the ankles. "These flies are attracted to dark colors, like blue, purple, brown and black. So wearing a light-colored shirt is a good idea-and wearing blue jeans might be a good choice, too, since that will help attract them away from your head. Insect repellents applied to exposed skin will provide some relief, though repellents applied to clothing remain active longer."