I have 2 female (100% female) mice, the one I had first absolutely hates the new one. (Which is weird because they are both definitely females) I went ahead and brought the exact same cage for the new mouse as I did for the original one. The original is fully grown and can not get out of her cage but the new one is smaller and can squeeze her way through the bars. What should I do as my mother just spent $40 on this and I feel bad telling her to buy me a new one. As she grows will she not be able to fit through the bars like my other one?