I have a few friend who obsesses about their neighbors cat constantly pooping in their yard. It drives them so crazy they have actually tried to trap the cat and spray it with a hose, in an effort to train the cat that their yard isn't cat friendly. Does it work? Nope.
Maybe the CatStop Cat Deterrent will help to keep cats out of the yard. The CatStop cat deterrent, by Contech, has a motion sensor that lets off an ultrasonic alarm when something crosses its path. The sound isn’t audible to humans but animals don’t' seem to like it. The CatStop cat deterrent will protect about 330 square feet of area and will set you back about $52 here.
Video after the break.