Small flies on Trollius

Small flies on Trollius

Observation - Small flies on Trollius. Description: Couple of tiny flies sitting on the petals of a Trollius (giant buttercup) in my garden in Edinburgh. Can someone at least give me the family name please?

Couple of tiny flies sitting on the petals of a Trollius (giant buttercup) in my garden in Edinburgh. Can someone at least give me the family name please?