I'm not sure that much else can be said, but things like this make me emotional, so I have to be honest and say that the idea disgusts me. I understand that cats who are allowed outdoors (or indoor cats who happen to find a mouse) would have a natural instinct to mice, but that is one of the many reasons that I have decided to keep my cats indoors only. I think it would be cruel to allow your cat to purposely do that, and I could not stand to watch it. Then again, I am a vegetarian, and I would never personally hunt or fish (not my idea of "fun"). There are plenty of interactive toys that can stimulate your cat and help satisfy the hunting instinct; they just require a little involvement on your part. I'm not meaning to personally attack you in any way, so I hope it doesn't come across like that. It does look like that you care about a lot your cat, and would consider extreme ideas to keep him happy, which is not such a bad thing. I just had to voice my opinion because I'm very sensitive to issues like this.