The Bell & Howell Solar Animal Repeller's high frequency ultrasonic sound is unpleasant to animals. It easily mounts to almost any surface but comes with its own mounting stake so you can place it almost anywhere. Once animals come within range, the built in infrared motion detector activates, both in daylight and even at night, emitting a powerful, ultrasonic sound that sends pests scurrying for safety. It works from up to 30 feet away. It’s weatherproof and solar powered.