Here in Houston, as of mid-September 2026, the house is shut tight against the heat, and anything scratching around at night gets noticed. My first move when I bought this place was the easy one: pick up a couple of those little ultrasonic plug-ins from the hardware store aisle, plug them in, and forget about them.
I put one near the pantry and one behind the fridge, figuring the high-pitched sound would send whatever was in the walls packing. No traps, no spray, just a small box humming quietly behind the appliance. I never went back and checked whether it was doing anything. I thought it was working because I couldn’t hear it. Turned out that’s also the only thing I knew about it.
Get the entry points found and sealed.Tell Nearby AI what you’re seeing and where, and it works out what’s likely going on, what the job involves, what it should cost and whether a quote is fair.“What should it cost to find and seal where mice get in?”→Free for homeowners · Your number stays private
What Cornell’s pest management program says
Cornell University’s integrated pest management program doesn’t mince words: “there’s no proof that ultrasonic devices really deter pests.” It goes further, saying scientific evaluations of ultrasonic devices have found no effect on target pests: German cockroaches, bed bugs and rodents.
Why they don’t deliver
On the mouse side specifically, a second university pest management program puts it plainly: “High frequency electronic devices aren’t effective.”…