I've used these for YEARS & never had a problem with ANY RODENTS or BUGS You just plugged them in & that's it. They last for YRS. Can't tell you how much I Love them!!!
Neighbor's dogs were barking all night and neighbors were too lazy to get up and stop them. I set it up under a covered patio and plugged it in overnite. Dogs learned quickly. I rarely have to use it now at night. It took less than a week for the dogs to self train. Too bad it doesn't work on the owners.
After 6 years of dealing with an unpleasant neighbor and his animal farm menagerie, we purchased a dog silencer.
Within 2 days we experienced a reduction in barking, within a week we actually slept through the whole night.
We were so impressed, we decided to get a second one and life quality drastically changed. The norm now is silence!!!
We also found out that the device doesn't work on birds (including chickens and pheasants), rabbits and cats.
From our experimentations we learned that two silencers work better and quicker than one, especially if you have more than one neighbor to deal with.
I've used these outdoors for several years leave 'em on full time day and night, rain and sun. Since I live on the coast in humboldt, they've taken a beating. Only ultrasound device I've used that survives the weather. I have 2 in a large vegetable garden, and they definitely work. Some of my original units are still functioning after 5 years or so.
Unit quit working. No questions asked. New unit sent, free!