Bats orient perfectly in complete darkness, relying upon their extra-ordinary echolocation abilities. In their world, bats are confronted with an immense amount of information, coded in echoes of their echolocation calls. Some information might be misleading, some might be essential for reliable orientation and object recognition. Thus, it is very interesting to investigate how bats deal with different kind of echoes. The first chapter of this book is about how bats, which heavily rely on information contained in echoes deal with misleading spatial information of echoes for accurate sound localization, both in active and in passive hearing conditions. The second chapter deals with the question how bats deal with size-induced variations in echoes due to different-sized ensonified objects. It was investigated if echolocating bats achieve a size-invariant, normalized object repre-sentation for reliable object recognition. This book is of interest for those, who are generally interested in psychophysical science and in particular in the possibilities of echo evaluation in bats.