I have never owned two mice at the same time (yes I was a very bad un-informed mother to my pet mouse when I was little..I was only 8 though!!) and I have two females. They are nearly 5 months old and they are always fighting!! They will not share anything and always insist on eating their treat in the exact same spot or whatever the problem is at the current time! They don't ever draw blood or anything but a couple of times every week I hear their little squeaky voices and they are chasing each other around the cage. Is this normal?? Is there any way I can stop it?? I know they aren't hurting each other bad but it sounds awful listening to them!