I had three of these units placed throughout a 600 square foot apartment (ground floor). Unfortunately, I had to squish a spider, silverfish, or unidentified bug almost every other day (in the summer). Sometimes, I fould find a bug just hanging out directly under the pest repeller! I did not notice a decrease in bugs at all.I can't say if this product repels mice or not. I never saw a mouse in my apartment before or after I started using the repellers.