I just had my mouse give birth and they're all almost 2 weeks old already. The babies all seem healthy and have a nice coat of brown fur. However, mum seperated four of her babies from the rest of the gang today. Four of them she keeps in the original nest while he other seven (which are generally bigger than the rest) are kept outside the nest and she nurses them outside as well. I don't know if this is temporary or not but i'm really worried. What could be the issue here do you think?