snipe fly, (family Rhagionidae), any member of a family of insects in the fly order, Diptera, that are dark-coloured and between 8 and 15 mm (0.3 and 0.6 inch) long and have a rounded head, posteriorly tapering abdomen, and long legs. Adults are usually found in wooded areas, and the larvae are found in soil or water. Although both adults and larvae are predacious, most snipe flies do not bite people. However, females of the genus Symphoromyia suck blood and are common pests on the Pacific coast of North America.