A new strategy to reduce the spread of COVID-19 employs a mobile robot that detects people in crowds who are not observing social-distancing rules, navigates to them, and encourages them to move apart. Adarsh Jagan Sathyamoorthy of the University of Maryland, College Park, and colleagues present these findings in the open-access journal PLOS ONE on December 1, 2021. Previous research has shown that staying at least two meters apart from others can reduce the spread of COVID-19. Technology-based methods—such as strategies using WiFi and Bluetooth—hold promise to help detect and discourage lapses in social distancing. However, many such approaches require...