A mite of approximately 1.3mm in length, that was found with a dead Aphodius rufipes dung beetle. The mites travel with the beetle to new sources of dung, and are likely oribatid mites that feed on fungus growing on the dung. Aphodius rufipes can also play host to parasitic mites that feed on fly larvae that live in dung.
From Wikipedia (http://en.wikipedia.org/wiki/Acari):
Acari (or Acarina) are a taxon of arachnids that contains mites and ticks. The diversity of the Acari is extraordinary and its fossil history goes back to at least the early Devonian period.
Most acarines are minute to small (e.g. 0.08–1.00 millimetre or 0.0031–0.039 inch), but the largest Acari (some ticks and red velvet mites) may reach lengths of 10–20 millimetres (0.39–0.79 in). It is estimated that over 50,000 species have been described (as of 1999) and that a million or more species are currently living.
-0.25 exposure compensation in ACR