The community and trophic structure of mites was examined in cattle manure and their response to treatment of manure with solid-waste particles was investigated. Mites were collected from artificial dung pats exposed to natural colonization in the field for 16 days. The pats were composed of manure alone or manure separately mixed with waste-material particles of four types and concentrations. Mites were the numerically dominant taxon among arthropods in manure. The Prostigmata was the most abundant suborder, mainly represented by the families Pygmephoridae and Ereynetidae. The common families of Mesostigmata were all cosmopolitan. Correlations with other arthropods suggest that Mesostigmata are opportunistic predators, preying upon dipteran larvae, Collembola and other mites, and preyed upon by larger predatory insect larvae. Cryptostigmata and Astigmata were a numerically minor community component. The species composition and abundance upon treatment of manure with polyethylene, polystyrene and glass particles was similar to that of the treatment control, i.e. natural and inert sand. Relatively low concentrations, 5 and 30% (v/v), of particles in manure did not alter the mite communities despite important differences with untreated manure in final moisture content. These findings may be relevant to proposed methods of solid-waste disposal. High particle concentrations of 60 and 90% had detrimental effects to the abundance of mites in manure and were caused by the very low final moisture content and probably nutrient deficiency of these treatments. The persistence of members of the prostigmatid families Tydeidae, Nanorchestidae and Tarsonemidae in the moisture-deficient 90%-concentration treatments supports previous evidence of adaptations to low-water-content habitats.