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There seems to be a dearth of bat detectors in stock in internet stores and I count myself lucky to have received mine before they all hibernate (the bats that is!). I am now the proud owner of a Ciel 101.
We are amazed at the huge amount of ultrasonic activity in the garden. We find no difficulty identifying both species of Pipistrelle (they fly around the bottom of the garden at dusk but seem to get closer to the house around 22:00).
Much, much louder is the very regular "chop" (just above one per second) of a much chunkier bat that hunts parallel with the line of houses. Its peak volume is at 22.5Khz but I can also pick up fainter warbles at 39khz (possibly harmonics, as they only occur when I hear the 22.5khz calls?) The bat appears to sweep across many gardens and then turn and retrace its steps. Because it is so loud it can be heard coming from some distance. I thought it might be a Noctule but I do not hear the chip/chop (just the chip bit- an FM sweep). I have listened to the recordings of Noctule, Serotine and Leislers on Brigg's and King's Bat Detective CD and while it has similarities with all of them it isn't exactly like any of them. I would be happy to receive any suggestions on how I might go about deciding which species it actually is, or indeed what you hunches might be.

We also seem to have a relatively static source of ultrasonic calls (36khz) on/in our shrubs and hedges. These insects(?) also chirp at about once per second and can be tracked to an individual branch. When I twist the branch look with a torch the noise stops. can't see the source though. Many of you with bat detectors will have heard this as well. Any ideas on what it is.
Thanks for any advice.