Mice living together
Mice are very sociable and are best kept with others.
Female fancy mice can be kept in same sex groups with usually no problems. Male fancy mice can and should be kept in groups, although there is more risk of fighting between them. To prevent this, we have all our male mice neutered. Male mice can also live with female multimammates. Either way, we strongly feel all mice should have company.
With groups of un-neutered male mice, we advise giving each of them their own items. So if you have 3 living in a group, they should have 3 houses, 3 bottles, 3 of each toy etc. This tends to help prevent arguments.
Introducing mice together
This can be used to introduce female mice or neutered male mice together. It is not advisable to introduce un-neutered male mice together as they will almost certainly fight.
Here, we have completed many introductions. Mixing multiple neutered male mice together, with female mice and multimammates.
Mice must be introduced on a neutral territory. A small tank or carrier with very minimal but fresh substrate. Do not add any toys at this point, just some scattered food.
Mice can be vocal with one another and do squabble, this is normal. Allow them to interact and only separate if either blood is drawn or if one is being a bully. Separate the bully and allow the others to continue to interact. You can add the bully back in 20-30mins later.
Monitor them for a few hours and is they all seem relaxed (ideally all huddled together), you can add a house for them to hide in. This can help with them cuddling up and exchanging scent.
We advise to leave them in a small space overnight, then move them to their tank the next morning. The tank must be clean, with no smell of any other mice. Avoid adding toys for a few days and scatter feed to prevent arguments over a bowl.