Theseus is a magnetic mouse, created in 1950, controlled by an electromechanical relay circuit that enabled it to move around a labyrinth of 25 squares. It was about the same size as an average mouse. The maze configuration was flexible and it could be modified arbitrarily by rearranging movable partitions. The mouse was designed to search through the maze until it found the target. If placed in an unfamiliar area, it was programmed to search until it reached a known location and then it would proceed to the target.