Contrary to most other lower flies, the larvae of the Stratiomyidae are not predators or parasitoids. They are aquatic to terrestrial and mainly feed on algae and rotting organic matter, in most cases of vegetable origin. The aquatic habitats range from stagnant to running water, moist rock faces, on water vegetation, marshes, saline environments along the seaside or inland. Terrestrial larvae often occur underneath leaves and other rotting vegetable matter, in the topsoil, in some cases in dung, in ants nests and below the bark of trees. The adults feed on nectar and honeydew. They are frequent visitors to flowers and are also found sitting on leaves of herbs, shrubs, or trees. Preferred habitats include woodland, the vicinity of water, dunes or other coastal habitats.
Small to very large (2-25 mm) flies of slender to stout shape, in some cases flattened. Body colour often striking: usually dark with conspicuous white, yellow, or greenish patterns, sometimes with blue to green metallic lustre. Eyes usually holoptic in male; antenna with 7-10 segments, varying between rather uniform to basal segments swollen and terminal segments making up the style; mouthparts often short, in some cases elongate. In most species scutellum with spinelike extensions. Wing usually clear, in some species with markings or partially much darkened; venation characteristic, e.g. R-veins in front part of the wing with vein R5 almost always ending well before the wing tip; discal cell diamond-shaped, small to very small; cell m3 open; cell cup closed. Legs simple, almost always without bristles, in a few species tibia of the mid leg with a single apical bristle; empodium pulvilliform.