PROJECT SUMMARY Where there is life, there is death. Death can occur due to a variety of factors, such as lack of resources, disease, predation, and old age. Thus, animals may frequently encounter the dead of their own kind (conspecifics). Although death is a common occurrence, how animals sense and respond to dead conspecifics remains curiously unexplored. By examining how fruit flies, Drosophila, sense and respond to dead conspecifics, this proposal seeks to elucidate fundamental questions about death. The overarching goal of this proposal is to characterize adult Drosophila’s egg-laying (oviposition) responses to dead conspecifics, and discern the mechanisms underlying these behaviors. While death is often viewed as an aversive state, this proposal uniquely studies contexts in which death has a positive valence, thus generating entirely new findings, as well as re-contextualizing previous work. Accordingly, this line of inquiry builds on a robust foundation, in which preliminary results indicate that: (i) in a binary oviposition assay, adult Drosophila preferentially lay eggs on the side with (versus on the side without) dead bodies and (ii) olfaction may play a critical role in these dead body preferences. Taking advantage of our laboratory’s expertise in and access to specialized chemosensory techniques, genetic tools, electrophysiology, and spectroscopy, as well as technical innovations I have developed, this proposal systematically, rigorously, and uniquely investigates how Drosophila respond to dead conspecifics.