Repel Rodents – Ultrasound Devices?

Q: I need advice on ultrasound devices that repel rodents. 

A: They are useless. The reason ultrasonic devices don’t repel animals, even though they can hear sounds we can’t, is that ultrasound does not pack much energy. A sofa, a kitchen cabinet, or a wall block almost all of the sound waves. Just as you might quickly roll up your car window when an ambulance howls past, a mouse or rat can duck behind a solid object to hide from loud noise. When food, water and shelter are present, a rodent can easily find different paths to them that avoid the ultrasonic sound waves.