A demarcating system for indicating the boundary of an area to an object (for example a robot, such as a robotic lawnmower), which has a receiver for receiving electromagnetic signals. The system includes a control system, a wire loop, a signal generator, and current sensing circuitry. The wire loop can be arranged by a user along a path, so as to indicate the path to the object as part of a boundary of the area. The signal generator is electrically connected to the wire loop in order to apply voltage signals thereto, such signals causing the emission of corresponding electromagnetic boundary indicating signals from the wire loop that may be received by the receiver of the object. The signal generator is under the control of the control system with the voltage signals applied by the signal generator to the wire loop being controlled by the control system. The current sensing circuitry senses current signals present within the wire loop and the processors of the control system analyse such current signals. The
