Got two new wibble babies yesterday, two male fancy mice that are white and black. One has long hair and is named Guybrush and the other is short haired and is named Murray.
They are 2-3 month olds and where housed in one unit with a third mouse, the first night together at the apartment and they where fine but we noticed that Murray has been pushing Guybrush around and there's a lot of squawking involved. Since I've only owned female mice prior to this we did some looking up and apparently in new enclosures with male mice one can try to become the dominate one and push the other around. This may mean some non-bitey kind of fights and squawking, but if one is fighting the other even when it's in the 'surrender' kind of posture he can be considered a 'bully mouse'.
I've got to watch them to make sure Murray doesn't bite or otherwise harm Guybrush, and the website recommended removing the bully for 15 minute 'time outs' so they learn that bullying the other means being resigned to their own empty cage as well as giving him time to cool off.
If Murray keeps bullying Guybrush even after repeated 'time outs' to cool down then I may just need to keep them apart, but that's a really last ditch resort because separted mice can get depression and be very unhappy. The bully will likely be unaffected by his solitude but Guybrush might get awfully sad so if I have to do that I'll need to make sure I befriend and handle Guybrush especially often. So I am hoping it doesn't come to a point where I need to keep them apart.
It's just very odd because they're both the same age, I believe from the same litter, and where housed together at the pet store without displaying any aggression. The first night the two where totally fine, and continued to be interacting well last night and this morning but once nightfall came tonight and they where active again it seems like Murray's really trying to be quite bossy. There hasn't been any injuries so I am hopeful that time outs will cool him off.
In possibly related news: His little mouse balls are enormous and may be caused by extra mousey testosterone.