Systems and techniques for the quickly and efficiently locating survivors in a disaster area are disclosed. In some embodiments, the system comprises a plurality of robots distributed into a disaster area where each robot comprises at least one processor. The at least one processor is configured to receive discover packets broadcast by one or more mobile devices located in the disaster area. Each discover packet comprises information indicating how many other mobile devices in the disaster area are associated with the broadcasting mobile device. The at least one processor is further configured to determine a path along which to move the robot responsive to receiving one or more of the discover packets. The path is determined based at least in part on the received one or more of the discover packets. The at least one processor is further configured to cause the robot to move according to the determined path.