The consensus from each study was that ultrasonic pest repellers have little to no impact on pest activity. The Federal Trade Commission (FTC) has also found that the claims made by some manufacturers are not backed by scientific evidence.
Do solar powered animal deterrents work?
https://www.youtube.com/watch?v=1-XXkPncQBY
Do Electronic rodent repellents really work?
Electronic mouse repellents operate under the idea of using high-frequency sounds to drive mice away from food sources and nesting grounds within human homes. However, there is little data that these devices repel insects or are effective in rodent control.
Do Sonic rodent 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.
How long does it take for ultrasonic pest repellers to work?
If you're experiencing a severe pest/rodent infestation, do your best to use ultrasonic pest repellers in combination with baits and traps. In this case, the devices will help you get rid of the problem within two weeks.