This was published by the German agency for nature conservation in 2004. Central Germany is very special because there’s a university with much batty-interest in an area with lots of bats, and they have sent many PhD students out looking at them. Over about ten years it’s built up into a tremendously detailed study which is what you need to try to understand them. This book assembles some of these studies. As you delve into their lives you see how complex they are, and this book tries to unravel the complexities.