There' a complicated chain reaction that led to these pictures.
I decided to take another picture of the bats flying in the garden, this time with a flash. It really isn't much effort because they seem to appear punctually at around 20 minutes after the sun sets, which has been around 6:30 or so for the last few days.
I found a flash gun and connected it to a camera and when the bats appeared I simply fired a few shots. The effect was almost blinding. A white wall of light that looked as if we were under alien attack. The bats seem unperturbed and carried on hunting for insects.
"There's lighting!" I could hear a neighbour calling out, "It must be very close!"
I decided to abandon the experiment which was starting to divert aeroplanes.
As I returned indoors I noticed that the camera was remote triggering the flash. Cue Tigger to pose for a couple of test shots.