My boyfriend had a couple of these devices in his apartment to deal with the persistent roach problem that was an issue in his building due to the number of residents who don't have much in the way of keeping their apartments clean. When used properly alongside appropriate cleaning and keeping a place free of what attracts roaches this device can work well. Don't just plug in and let it do it's job you also need to keep your house clean and free of things that attract pests. You are going to have to do a full and concise cleaning of cupboards and cabinets where roaches and other pests can take space. Plug in areas throughout the home or apartment. If you have a house you will have to get more than one for it to be effective. You're advised not to use these if you have pets like guinea pigs, hamsters, gerbils, mice, and rats because it's also designed to repel rodents as well. It has no effect on household pets because the frequency is not enough to bother the hearing of a dog or cat. Again for this device to work you also have to incorporate regular cleaning to get rid of what attracts rodents and pests.