No interactions present.
The second picture makes this ID more likely. Though, what it is eating, I cannot guess at!
My Flickr photos...
I can't be sure of this, but the prey looks rather like a fly from family Sphaeroceridae, which would mean that a dung-fly is preying on a lesser dung-fly. Presumably an interaction that happens quite often since they occur in similar habitats.
Entomologist and biological recorder
Lat/Lng: 51.63989, -3.00508
OS grid ref: ST305939