A group of two e-puck robots are evolved for the capacity to reach and to move back and forth between the two circular areas. The robots are provided with infrared sensors, a camera with which they can perceive the relative position of the other robot, a microphone with which they can sense the sound-signal produced by the other robot, two motors which set the desired speed of the two wheels, and a speaker to emit sound signals. The evolved robots coordinate and cooperate on the basis of an evolved communication system which includes several implicit and explicit signals constituted, respectively, by the relative positions assumed by the robots in the environment as perceived through the robots' cameras and by the sounds with varying frequencies emitted and perceived by the robots through the robots' speakers and microphones.