Efficacy: The rodent repellent can keep moles and voles away from your garden. The device will vibrate on the ground, which will disturb the animals and find a better place. Sound waves: Vibrate once every 20 seconds, and the frequency change reduces the influence of habituation. Battery Powered: Powered by solar cells, no extra battery needed. The device will be automatically powered by the sun during the day to keep working at night, which means all visitors unwanted will not be able to enter your home. Large effective working area: The device operates in a circular fashion. For best results, we recommend installing 2 devices per 100 feet to face the floor area where pregnant women often enter and exit grain.A