I know the title seems pretty abhorrrant. My daughter had two rats, one recently developed breathing problems, a common problem in rats, and had to he put to sleep. The rat that is left was always more timid and not as friendly as the other one. We have tried to make him comfortable and happy but not having much luck. Won't come out of his cage and barely moves. We've even brought the cage into the living room but he isn't interested and is obviously not happy. Rats need other rats to live with and don't like to live alone but we aren't getting any more rats for definite and I don't want to try and rehome him as he's probably only got a year left at best and I couldn't bare some idiot try and feed him to a snake.
Is it ethical in this situation?