Although beaked whales remain a cryptic and elusive family, much has been learned about their dive and foraging behavior in the last few decades through the use of passive acoustic monitoring (PAM) and a variety of tagging methods. Species-specific echolocation pulses can be used to acoustically track individuals and groups, and biologging tags provide information on dive and movement behavior. These technologies have also provided a window into how beaked whales behaviorally respond to Navy mid-frequency active sonar, which in turn may elucidate maladaptive behaviors that could lead to stranding. This chapter reviews existing knowledge about beaked whale behavioral responses to anthropogenic sound sources in general, and to Navy sonars in particular. By understanding the breadth of ways beaked whales behaviorally respond, the scientific community can continue to work toward recognizing and mitigating responses that could lead to stranding, as well as determining the population-level implications of impacts on individuals.