Daubenton's bat

Head for still water. Daubenton's bats hunt over lakes, canals and slow rivers, flying steadily within a few centimeters of the surface like a tiny hovercraft, and they have even been seen taking prey straight off the water. Find a bridge or bank with a clear view of calm water after dark and sweep a low, dim beam across the surface: the bats show up as pale flickers skimming the reflection, then vanish again. It is one of the most watchable bat encounters in Britain and an easy one to share with children. On a detector their calls are loudest at around 45 to 50 kHz.