Winter gnats lekking on a winter afternoon.

 A freezing cold afternoon, but a swarm of these winter gnats Trichocera sp. was dancing, in a shape-shifting column, above the garden hedge this afternoon, catching the last rays of sunlight as the sun was sinking towards the western horizon. They would have all been males, lekking, attempting to catch the attention of a female.

The flower border beside the hedge is covered in a thick layer of decaying autumn leaves - just the kind of place where the females will lay their eggs.

There are come close-up pictures of winter gnats here