I come across this shiny green dung beetle quite often whilst walking on the hills in Galicia, NW Spain. It mainly seems to like horse dung, and I look out for them when there are Galician ponies about.
The beetle is a very shiny, metallic green colour, with a distinct reddish hue, on the upper or dorsal surface; underneath they are shiny blue. These beetles are so shiny that you can sometimes see yourself reflected in their pronotum (back) or elytae (wing cases), as shown below. I have however, occasionally come across much duller coloured ones, which have presumably just emerged from underground, or feeding on dung. They also have lovely, shiny blue legs!
I think these dung beetles are a type of Trypocopris (=Geotrupes) pyrenaeus, either T. pyrenaeus var. coruscans or T. pyrenaeus splendens. A picture of a beetle – T. pyrenaeus var. coruscans – which looks very similar to the ones shown here, can be seen on this Spanish site of Galician arthropods (1). What characterises this species (T. pyrenaeus) are: i) distinct striae on the wing-cases; and ii) and a distinct marginal ridge, or flange, around the entire base of the pronotum. The reddish sheen is also diagnostic. So these beetles seem to fit the description for this species, although it is difficult to go entirely on photographs alone. Some magnificent pictures of Geotrupid beetles can be seen on the site called World Wide Beetles (2).
These dung beetles are good parents take care of their young. Both males and females are earth-boring, and burrow down into the soil to construct brood chambers, where they rear their larvae. They provision the chambers with dung for the developing larvae to feed on during a long development period, up to 8 months to a year I believe. If you pick them up and handle them, as below, they eventually get fed up and fly off!