Abstract: We study the neural basis of natural behaviors, in particular navigation and social behaviors – taking a “Natural Neuroscience” approach. In my talk I will discuss three recent studies: (1) Our recent discovery that in social groups, hippocampal neurons encode rich social signals – including the identities, sex, hierarchy, and affiliation of other individuals. (2) A coding-transformation that we discovered in the hippocampus of bats flying in a very long 200-meter tunnel – from sparse coding in hippocampal area CA3 to dense coding in area CA1. (3) Neuroscience in the wild: recordings of place cells and head-direction cells in bats navigating outdoors on a remote oceanic island near Zanzibar. These three studies demonstrate different levels of experimental control vs. ecological validity in our efforts to understand the neural basis of behavior.