Posted by a reviewer on Amazon

One is the normal ultrasonic sound that is supposed to drive away pests and a second setting that is supposed to drive away rodents more aggressively

Posted by a reviewer on Amazon

On the second mode you can actually hear the screeching and if mice find it half as irritating as i do they will leave and not come back

Posted by a reviewer on Amazon

I have tried everything else from dryer sheets which didnt work no matter what brandscent i tried to moth balls which seemed to help but gave my wife headaches to another brand of utrasonic repeller which seemed to help a while and then the mice came back

Posted by a reviewer on Amazon

The insructions say to have it on mode 2 the horrible screechy mode for a while to drive them out then switch to the standard mode for a while and then only use mode 2 for a couple days every once in a while to prevent mice from becoming tolerant to the noise

Posted by a reviewer on Amazon

I plan to follow the instructions although i cant see how anything could get used to such an annoying screech think fingernails on a chalkboard times 10

Posted by a reviewer on Amazon

Even if it doesnt work forever it didnt cost an arm and a leg to try

Posted by a reviewer on Amazon

About two weeks after installation i stopped seeing any insects in my bedroom at all

Posted by a reviewer on Amazon

Seems like they work as i see less bugs in areas where i normally always saw bugs and its summer time when the bugs are numerous