Control systems engineering commonly relies on the “separation principle”, which allows designers to independently design state observers and controllers. Biological control systems, however, routinely violate the requirements for separability. Indeed, animals often rely on a strategy known as “active sensing” in which organisms use their own movements to alter spatiotemporal patterns of sensory information to improve task-level control performance. In this seemingly paradoxical category of behaviors, animals generate movements that are not directly related to the motor goal and superficially can appear to be counter to it. These movements, however, appear to improve sensing in the closed-loop system, likely increasing control performance. Here, we examine sensorimotor control and active sensing in an ideally suited organism, the weakly electric glass knifefish, and show that these fish change their active sensing behavior in a manner that “adapts” to the availability of sensory information. This is joint work with Eric Fortune at the New Jersey Institute of Technology.