A mechanical animal repeller is a device for deterring animals that does not use electrical energy or batteries for its operation. Its activity is based on natural forces, most often on wind power. It can take the form of various pinwheels, propellers, or hanging objects such as aluminum strips or old CD discs. These elements move, rotate, and often reflect light due to the wind, thereby creating unpredictable visual and sometimes auditory sensations. The goal is to disturb animals, for example, birds, deer, or wild boars, and deter them from entering a protected area such as a garden, orchard, or field.