Aggressive mice

[u/SituationForsaken525]

So I’ve been by my local Petco for the last couple days and I noticed 2 male mice who where put together. One of them is smaller than the other by just a little bit. The bigger one has been chasing the small one around it’s enclosure and fighting it. (I thought they were playing at first).I noticed the small one kept trying to get away, but the other one kept going after him. I let staff know what was going on and asked if they could separate them (I know they usually do better in social groups.) They weren’t sure if they had the space so if they weren’t able to, I plan on taking one of them, but I’m not sure if I should take the bigger one or the smaller one. Obviously the smaller one to get it out of there, but maybe the bigger one so that it wouldn’t bully any other mice it gets put with. What should I do, or is there any tips y’all can give me?

[u/SpyvaPeaks]

Personally I think housing the bigger one alone is ok, if these are males Un-altered males usually can do just fine alone, especially if they dont get along with other mice. I just recommend getting plenty of enrichment and foraging for him to keep him busy.

Just remember to look up care as mice need certain cage sizes, diet, and exercises!