My mom has been trying the ultrasonic/electronic deterents for years. Everytime she comes across a new version, she's buying it...all to no avail. Tom, I'll suggest she go to Lowes and give theirs a try, thanks. She refuses to use anything that might actually KILL THEM...For the life of me, I don't know why!!! I didn't mean to come off as "Mr. Know-It-All" about the cat remedy, it just has worked for me for many years and we do REALLY have allot of the little edibles up here. Whatever you choose, I hope it works. for you.