Sue, thanks for some info about someone's experience using something similar!

Maybe the technology works.

After several people reporting that the mosquito units didn't seem to work and my mother's experience with some "Mole Chasers" that didn't work I wasn't sure if this would work either.

We could hear the ones used up at the cabin, but it was just a click followed by a short burst of high pitched noise, almost like a camera flash charging if I remember correctly. It would go off every ten minutes or so. Even so, it didn't interrupt our sleep or anything, and the cabin was only about 40' x 20' at best guess.