A lawnmower (100) is described comprising an ultrasound deterrent device (3) for wild animals, means for controlling (1) the ultrasound deterrent device and detecting means (2) adapted to detect an angular deviation of the lawnmower with respect to the trajectory thereof； the controlling means are configured to process the angle (α) of the angular deviation from the trajectory (L) of the lawnmower from the data received from said detecting means and are configured to activate said ultrasound deterrent device if said angle (α) is greater than a given angle (α). (Figure 1)
