It took the attack wave pestrepeller about 5 weeks to clear out the pest (rodents)in my home. I live in an area that is surrounded trees and nature, so I had a problem with mice coming in when it gets cold. I bought 2 of the repellers, one for upstairs, and one for the downstairs area. I could hear the rodents at night and see them in the kitchen after everyone settled down for the night. This was quite disturbing for me, especially after purchasing this product, but I read that it could take up to six weeks for the pest repeller to work. The 4th week the mice sounded as if they were trying to eat the house up. You could hear them clawing like they were trying to find a way out. The next week no noise, or any evidence of any mice or any insects in my home. This product is wonderful.