Id release him but thats just my opinion Ive never really been one to go out and catch snakes and bring them home. I was always worried they would have something that my other snakes could get and Im sure they are happier out there then in a cage in my room lol You could try to offer him some food though that way he could at least get a good meal in him before he went back in the woods to hunt. Copperheads are great snakes I love them and think there are just gorgeous. I could stare at my little girl for hours