Small black fly resting on a gorse flower by Keston Ponds.
No interactions present.
This was my sighting, posted yesterday...
There are other very similar species, though. You need to see the two spines on the front tibia, as a starting point to go further.
My Flickr photos...
Thanks. I have only very basic references for insects other than the Lepidoptera!
Lat/Lng: 51.359111, 0.036137
OS grid ref: TQ418641