I have the same question , I work in a down town store in my city behing the main street runs a river with 50+ ferral / wild cats living on it , my city seems to do nothing about all the cats if live traps are set then people will vandilize them , and some ppl feed thease homless cats several times a day many diffrent varities of food , wich means lots of poop, the back enterance of my store has a large gravel parking area enough space for 12 cars well guess what all 50 of thease well fed cats have taken up our gravel for the verry large and might I add verry stinkey litter box , I have been told mothballs , but I also hear its dangours , I have been told chilis but also here the same , I don't want to hurt these guys I just want to encourage them to use the bathroom someplace else , and one have any sugestions, shooting them killing them poisioning them is not a option for me