I am no longer breeding mice. I suggest when you adopt or buy mice that female mice be adopted in same sex pairs, or in groups of three or more, as mice are social animals and need to be in each other's company and would otherwise suffer.

In the case with boys, they do better as single pets with someone that will spend time with them playing and being good companions to them.

Two boys together will get along when young, but as soon as they hit puberty they will end up fighting badly and therefore it is best to have them as single pets with lots of undivided attention.:)