A small (7-10mm) Cryomyia sp, most likely undescribed shown here hovering above a hole that may have been an ant hole (unsure). The fly would drop and while flying flick sand into the hole. Possibly laying eggs and flicking them into the hole.
Yeates, D. (1996). Revision of the Australian bee fly genus Neosardus Roberts (Diptera : Bombyliidae). Invertebrate Systematics, 10(1), 47-75. doi:http://dx.doi.org/10.1071/IT9960047
