Adults characteristically wave their wings outward while walking about on various substrates.
Larvae are scavengers and are important decomposers of animal excrement, carrion, and decaying vegetation. Some can be considered of some hygienic importance due to their association with human feces. Some species can be found in large numbers in sewage sludge. The fossil record for this family is poor, there being only five described species in three genera. Except for the North American Oligocene Florissant fossil Themira saxifica Melander, all are found in various Tertiary deposits in Europe.