Nervous systems evolved to control behavior. A primary function of nervous systems is to receive and process information from the outside world, and then act on that information in ways that maximize survival and reproduction. We use an integrative approach to study animal communication and the evolution of sensory processing, using weakly electric fishes as a model system. Our work is unique in its application of detailed neurophysiology within a comparative behavioral framework, and it has implications for our understanding of neural mechanisms for behavior as well as the evolution of behavioral diversity. We employ a wide range of techniques, including in vivo and in vitro electrophysiology, anatomy and histology, neuronal imaging, computational modeling, behavioral observation and playback, molecular phylogenetics, population genetics, and field work.