 I would find a way, if you can, to deter those cats. If they're owned cats, and if you're certain whose cats they are, you said your neighbors, then you could try to appeal to the neighbors to keep their cats indoors and tell them what's happening with your cats. And this is a common issue. You're not alone. I get this all the time, and it drives me crazy, and it drives you crazy, rightly so, once you know what it is. Because it's not fair that their cats...