I study how organisms integrate sensory information from multiple modalities across time and space to make decisions in complex naturalistic environments. My end goal is twofold: to understand how brains process sensory information, and to generate new, bioinspired, algorithms for engineered systems that enable the kind of resilience characteristic of biology. In my talk I will describe recent work in my lab that leverages optogenetics in freely flying fruit flies to remotely activate their sense of smell. Using this approach, we have characterized new olfactory search motifs that they use in still air and unsteady wind, supporting a unifying algorithm for olfactory search across flow regimes. We also show that flying flies are capable of estimating the presence and direction of ambient wind. To understand how they might achieve this my group developed new control-theoretic tools for empirically assessing the nonlinear observability of individual states—that is, what sensor combinations and movement motifs are required such that wind direction can be estimated. Finally, I will describe our preliminary efforts to design nonlinear observers for wind direction, and describe a framework for how this approach could lead to estimation strategies that are resilient to unanticipated measurement anomalies.