I bought a male and female pair from the local pet shop in early August. Male is doing well. The female isn't. She isn't growing, has a poor coat, is small, and not very active. The male is easily twice her size. She tends to lay around a lot. All my other mice are doing great. Growing, gaining weight, very active. Same food, etc.

Any ideas on what I should do? Keep her and try to make her better, or give up and give her to the snake?