We are putting in a chain link fence at the back this weekend and plan to fence off the front of the yard in the next couple of months. That might deter them a bit but I know that kitties go where they want to! I've seen these guys leap over the stockade fence at the side of the yard in a single bound!

Thanks for your input - I know there might be some folks who don't agree, but I'm going to trap them and get AC to pick them up. You are right about the owners - if they care about the cats they will look for them at the AC headquarters in our county. Or if the cats are microchipped, AC might contact the owners and let them know that they are in violation of the county ordinance that say animals are not allowed to roam (there is an ordinance like this; I checked).

When I landscape, I'll use the cedar chips as a deterent. But I think I'll look for the Feliway too. I'll spray that near the bird room window so that the cats give that spot a wide berth.