Ultrasonic Repellers Don’t Repel Animals—Unless You Throw Them

Q: Several dogs with unknown owners have been pooping and peeing on my front lawn. Is there some ultrasonic gadget that would keep them away? 

A: Sound repellers have been tested almost invariably on rodents and insects — which are not analogous to dogs. The first issue, of course, is that these repellers are making only sound. The theory is that dogs will be surprised and irritated, and therefore will avoid the area. Rural dogs might try to avoid ultrasonic sound, but canines in urban areas hear extremely high sound frequencies all the time and can become conditioned to them.  

It’s not the frequency of the sound that makes a difference to a dog: it is how unusual and threatening it is to them. If he finds the sound frightening, a dog will theoretically stay away. The second problem is that, the higher the sound frequency, the smaller its beam width, so it covers only a limited area. So it’s not particularly useful if you are trying to cover a large area. Ultrasonic repellers do not work to repel any animal unless you throw it at them.