I've got two somewhere in my house right now I've spent some time trying to kill. Rascals followed me in.
A couple years ago I got one at hf. a fly landed on it, I pushed the button and blue electricity covered the fly making it shake like crazy but there was not enough voltage to kill it. Hit the button several times and it just tortured the fly.Don't waste your money on the harbor freight units, they are junk.