male mice fighting HELP!!

Question
yesterday a family friend of mine give me there two male pet mice because they didn't want to look after them. i left them in the garage that night. the next morning i found that the two mice were fighting with each other! one had scratches with dry blood every where. i got scared so i took one out but then decided to put them back together. as soon as i did that the started fighting again. so i took one out again. now i don't no what to do. I'm scared to put them back together incase the start fighting again!!
please HELP!!

Answer
Dear Michelle,
thank you for your question.
Male mice won't  live together peacefully in 99% of all cases. Since they are already fighting and youo separated them, there's no way to put them back together, they will keep fighting until one of them is dead. If you can find a vet who will neuter mice, you can do that and them keep them both together with female  mice, but not with each other. You just need to keep them alone for at least six weeks after neutering because they may still be able to mate successfully once during that period. www.rmca.org/Vets has a list of good mouse vets.

If you cannot neuter them, you can keep them together with natal rats or white-footed mice, those species both get along well with fancy mice. It's not ideal, but that way they will at least have company. Mice are very social and shouldn't be kept alone. There should be at least two animals of the other species. White-footed mice are very interesting to watch, but need room to climb, they are extremely active. Since they can carry the Hanta virus, make sure you don't get wildcaught ones.
http://www.avidpet.com/rodents/whitefoot-mouse.htm
http://animaldiversity.ummz.umich.edu/site/accounts/information/Peromyscus_leuco...
http://goto.glocalnet.net/natal/
http://www.jirds.cwc.net/rag/profiles/nmmr.htm

I hope I was of some help to you
Jennifer