The Big Cheese Ultra Power – Mega-Sonic® Plug-In Twin-Speaker Pest Repeller - Professional Ultrasonic Technology Repels Mice & Rats Instantly - Indoor Electric Powered Plug-in – Pet-Friendly

I have used one of these for years. it works very well in our kitchen, in conjunction with good housekeeping measures. A hungry rodent will put up with the discomfort if it can smell food waste. if it can't smell food it will stay well away. Empty waste bins every day. it says on the packaging to allow up to 28 days for a full deterrent effect to occur. This device definitely gets my vote. Incidentally, the delivery was poor. The driver knocked briefly on our front door. He did not wait for us to answer. He left the package on the ground adjacent to the front door. By the time we opened the door he had gone. This was less than 2 minutes from knocking. He certainly did NOT hand the package to the customer as is stated on the final delivery note.

It is always hard to tell how effective these things are but my loft has been mouse-free since putting a few of them up there. The incessant beeping when the battery needs replacing is a bit bothersome for something that is typically placed in an inaccessible area and can't immediately be tended to. Batteries are lasting around 3 to 4 months for me.

It did not work at least at first so I bought another one and place both ends of my attic we have had no mice in 5 months in house or attic. I also sealed up all holes I found near kitchen pipes with wire mesh I recommend this. Recharge the battery's every 2 months

I have an open fireplace where every few years a mouse may come in. I have had a Sonic repeller plugged in adjacent to fireplace for years and have not had any rodents coming in. I recently had a mouse so thought to buy new sonic repellers. Purchased two of these plugged in either side of a 13 ft x 13 ft room. Did not deter rodents. In fact rodent made a nest directly below where one of the sonic repellers was plugged in! Invested in mouse/rat traps and used peanut butter and stem ginger cookies which caught and killed two rodents in fireplace. Now trying mesh and steel wool to block off future entry. Would definitely return these two useless sonic repellers if I could. Complete waste of money!

One of these kept a mouse away from a shed , I bought more for my loft after hearing noises and finding droppings. They were definitely working but did not deter these small house mice. I had to install traps to solve the problem.

Perfect, good value

I had a mouse/rat problem in my garage, they weee getting in car and chewing things. Since having this I haven’t had any more problems. Excelllent wildlife safe repellant

Who knows if these things work or not. I can't see it repelling active mice because it only emits a single high-frequency bleep every few seconds - but I think it might deter them from nesting in that area, hopefully. After all, they wouldn't be able to sleep with it going all night and day, so would presumably go elsewhere.