Feeding behaviour studies with three species of oribatid on ten species of edaphic salt-marsh fungi are described. It is suggested that these oribatids are mainly fungivorous and that Hygroribates schneideri may also take filamentous alga. All the oribatids have food preferences and the preferences of the juveniles often differ from those of the adults. Feeding behaviour studies with four species of Mesostigmata on seven types of food are described. It is suggested that Pergamasus longicornis and Cheiroseius ( = Sejus) necorniger are the most active predators of the four, that M acrocheles subbadius is a carrion feeder or a coprophile, and that Ololaelaps venetus can only take the smallest and weakest of prey species.