Ultrasonic pest control

I doubt you'd get whole house cover with a single transducer, as ultrasound is fairly directional and tends to be readily absorbed by furnishings.

 

From Wikipedia:
"Ultrasound generator/speaker systems are sold as electronic pest control devices, which are claimed to frighten away rodents and insects, but there is no scientific evidence that the devices work."

 

For some reason, I can't edit my former post.
I want to add that the Wikipedia quote is followed by source references, which I leave to OP to follow up on, or not.

EDIT: Now this is odd. The forum is letting me edit _this_ post. But it still won't let me edit my 1st post.

 

There is also the possibility that the ultrasound could attract pests (e.g. if it mimicked the mating call of a mosquito or whatever ).

 

About 40 (or more) years ago I looked into these ultrasonic pest devices when I lived in a roach infested apartment building.
My experience was, it took me a long time to find a piezo speaker that actually output the frequency I built my circuit to produce, because manufacturers falsely claimed frequency responses the piezo elements didn't actually achieve. So I'd be suspicious of any 'made in China' unit on the market because they have about zero quality control on their stuff.
My observation was, that after about 3 days I noticed a slight reduction in the roach population, I surmised that the unit MAY have been an irritant to a nest but only because I was using it in the kitchen, directed AT the under the sink area where they tended to be most prevalent. The downside was the experiment was a failure because roaches from the apartment next door would still come in on forays.
My conclusion was that my circuit MIGHT work if directly pointed at a specific area, over a continuous period of time, but wouldn't cover any other area, like kitchen cupboards or counters. But I may have been wrong about that. So I believe in actual practical usage, the ultrasonic pest repeller devices are impractical at best, and possibly completely useless.
As for whole-house coverage, that's a pipe-dream.
The ONLY thing that actually worked to virtually eliminate the roaches in that apartment was the liberal application of boric acid. Took a couple of weeks for full effect, but did the job.
If roaches or ants are your issue, that'll do it. Good luck if your pests are something else.