I purchased this product, about 2 weeks ago, in the hopes that this type of pest repeller had improved since the last one I attempted 5 years ago. This item has a thoughtful design, including a pass-thru plug (2 prong) and nightlight, and the innovative addition of an air ionizer that made placing this in a bathroom or closet a multi-purpose solution.
When I first plugged the unit into my downstairs bathroom outlet, my 2 cats 30 feet away in the living room started to growl and ran upstairs. My child came downstairs shortly afterward complaining about the painful warbling sound coming from downstairs. Apparently the ultrasonic frequency is outside of adult hearing, but adoloscent ears have a hammer and anvil response range beyond that of adults (until they're done growing, and the body loses flexibility, such as when the bones start to harden). I further tested the unit in the garage and an upstairs closet, but found the results were the same for both cats and family.
I am unsure of how pests respond to this unit, but it definitely repelled my cats and child, forcing me to discontinued use of the product.