How can a sonar/ultrasound pest control unit be DIY?

I've seen ads for pest control units that transmit some sort of signal that drives bugs &rodents away... friend had one & she didn't even get flies... but not sure which ones really work, and so expensive..... Would love to find a DIY Instructable on this! It would save money, the environment...etc...

benthekahn8 years ago
Here is a solar powered one for $8. I got a few from this site.
toelle8 years ago
Doesn't they use a speaker emitting a very deep tone? Just figure out how many hz they use and make one yourself.
SabraM toelle8 years ago
Save your money. They do not work. I bought some out of desperation, plugged it in, and almost immediately had roaches playing on it. They loved the blasted thing.
DHeights8 years ago
There are several university studies that show that ultrasonic devices don't work. Here are just a few of them: Colorado State University Cooperative Extension: Ultrasonic devices have not been proven to control mice. University of Nebraska - Lincoln: Considering Ultrasonic Pest Control Devices? Save Your Money Ohio State University Extension: Ultrasonic pest repellers are not effective in controlling flies and other insects.