Mice are dying?

I have four mice (1.3) that are breeding. They had two litters a while back and its been a while now. Recently I found that one of my mice had an abrasion on the top of its head, it really just looked like a small hole. That was a week ago and I figured they got into a fight. Today the hole was bleeding and running all the way down to its nose and another of them had a similar abrasion right behind its ear. Someone please help.. do they have parasites? Are they fighting? What should I do with/to them?

THanks so much.

Sounds like you have an aggressive one that is attacking the others, probably the male. Once they break the skin they will keep at it until death. Check out the others and you may find problems with them also. I believe it happens more often when the cage is overcrowded but I am not positive of this. Maybe it is time to kill off the breeders and start over.

Mites will also cause this to happen. I have seen when mites get into a colony, it will cause them to kill the young, regardless of the age. This could be another reason.

Its 1.3 in a 10 gallon... I went and checked the others, but they were all curled up together even the injured one and none had other injuries.. the other ones ear is already healed up completely which seems extremely fast

A ten gallon tank as in glass?? Thats not the best for ventilation. Ferrets cages work great. Did you say you had three? I would give them some more space. IMO

Well it has a wire top, not screen but wire. Should not that take care of ventilation? If not I'll move them. BTW, no more probs sense last post

Well me personally, and I just got my first two four days ago! lol I have noticed though they do stink! They can be litter trained. My one isn't yet though, so I'm cleaning their cage every two days. Are yours litter trained?? Its just being stinky and being in glass I have read will make them highly susceptible to respiratory infections. I myself would feel better having them in a cage. They get more air that way.

mine are in my room i never smell them.. it must be more ventilated than it sounds to yall, but i clean it often enough to keep it from smelling, not every 2 days though.

haha, the hamsters, i do smell tho.. smell horrible, they are in a well ventilated cage tho