Effective Solar Powered Rodent Repeller --- For optimal performance, we recommend placing one rodent repeller every 96 feet on your lawn when setting up your yard. It emits a 3-4 second sonic pulse every 40 seconds, which penetrates the ground and drives the pest away from the area where the sound is transmitted. Safe to Use --- Humane and safe around pets and children Mole repellent spikes repel moles by emitting a sonic pulse. They do not harm any animals in any way, as they do not contain any chemicals, poisons or dangerous ingredients. Effective and Wide Coverage---The ultrasonic pest repellents emit low-frequency pulses for 3-4 seconds every 20 seconds, which penetrate the ground and prevent moles from entering protected areas, as moles are sensitive to noise and vibration and it is an effective method to prevent them from damaging outdoor areas such as lawns, yards and gardens. Solar Powered - Economical and Safe---Built-in high-quality polycrystalline silicon solar panel, the