Groups of male butterflies may congregate in this way in order to gain nutrients which may be passed to the females during mating.
Mud-puddling - Wikipedia
Is male puddling behaviour of tropical butterflies targeted at sodium for nuptial gifts or activity? (Biological Journal of the Linnean Society)
We also saw a number of Painted Ladies. There was a huge influx of these butterflies from Africa in June, and the ones we are seeing now are the second generation.
Other butterflies we saw today were Peacocks, Small Tortoiseshell (below), Ringlet, Red Admiral and Meadow Brown.
In the last few days we have also seen some other insects which we were unable to identify. We aree very grateful to Ben Darvill, Jeanne Robinson and Les Larkman for help in identifying them.
At first I took this hoverfly to be a bee. Its black and white colouration was very striking. It is Volucella bombylans, which confused us because it is variable in colour.
The fly shown below is a male Bibio pomonae or "Heather fly." It is most noticeable when flying, as it dangles its hind legs in flight. It appears to be very common as we see it most days in large numbers.
The very short antennae and the red upper sections of the front and back legs should have made identification easy, but it wasn't in any of our insect books.