Any way you could slowly sneek them out one at a time? I hate to say this, but my sister did the same thing a while back. She had to two cats, didn't get them fixed, and they had kittens. Then the kittens had kittens.....they started going over to my parents house and jumping on Jewel when my parents would feed her, just to get her food because they weren't getting enough. I finally got tired of it, and, well, my sister doen't have any of those cats anymore. And she is stupid enough to believe that they just ran off. Just recently she rescued two kittens whose mother was ran over. She has been keeping them inside and is taking good care of them. I know....I've been watching her. But, if there is a way you could do that, without getting caught, it might slowly work. It took me months.