The problem of trying to snap bats!

They were out in force this dusk just gone and they are hard to capture at the best of times but this is their time when they feast on the plenty of mosquitos we unfortuntely get here, especially at the start of a heat wave (coming now). I sometimes try to capture them in honour of the sterling job they do (I react badly to mosquito bites!).
I can only find two and I thought I had got a dozen or so in shot!