Ultrasonic pest repellers, once plugged into an electrical outlet, operate by emitting short wavelength, high-frequency sound waves that are too high for humans to hear.

Do ultrasonic mice repellents really work?

The short answer is no, ultrasonic rodent repellents don't work. Some homeowners have noted an immediate effect at first, but over time the rodent problem will continue to persist.

Do sonic pest repellers really work?

In summary, ultrasonic pest repellers emit high-frequency sounds that manufacturers claim reduce household pest infestation, but laboratory tests have shown that the majority of such devices do not work as advertised, in violation of FTC guidelines.