It has been a really hot day, no cloud and no rain! Sat by the pond after 10 pm to spot bats. I have a BatBox 111 which was picking up bats at 40Hz. Likely to be Pipestrelles. Saw 2 or maybe 3, they were going so fast it was difficult to count them. Not as many as a few years back when maybe 10 or so appeared at dusk. Several large crack willows have been lost in the area over this time due to old age and storm damamge. Suspect that these were the roosts or nesting sites.
Go to the London Bat Group Site to listen to Pipestrelles:
http://www.londonbats.org.uk/batdets.htm
Long Tall Shorty
..caterpillar treat