I have seem them on TV. TV said they work. The laundromat seemed to have a lot of bugs flying and crawling around. We pay a pest company each month to spray. The laundromat is not air conditioned don’t make enough money to put air conditioning in yet so the doors are open a lot in the summer. So I thought I would try an ultrasonic but deterrent. Looked all over to find one. Got two at the local CVS store. Plugged them in at the laundromat and with in a week the amount of bugs flying and crawling around has been greatly decreased. We did have bees flying around a couple of weeks ago but most if not all the other bugs are pretty much gone.
I say they work.