Female Fancy mice

Question
I purchased four mice with a Ferplast gage at christmas.   Recently I was given a 4 foot glass tank and so  we decided to get another mouse, but when we got there with the kids we ended up with 3 new mice.  We put them together after spraying all of there backs with a little rodent friendly disinfectant and the cage.  Last night they made such a noise and I am afraid that the old mice is bullying the younger mice.  every time the babies come from the nest the older ones chase them off..... I am really worried and I don't know what to do.....  will they work it out?  or will I have to separate them?.   PLEASE HELP the babies squeak like they are being killed.....

Answer
Hi Nicky,

Are you positive they are all females?  Mice have a social order, so each time new mice are added they have to work things out.  I have seen some females that absolutely WILL NOT be housed with any other mice, but there are usually other things you can try first to get them to get along.  If any blood is drawn, or you see serious bites or injuries, you will have to separate them however and treat the wounds immediately with betadine disinfectant diluted to the color of tea.

Here's what you can try in the meantime, if none of the battling is serious:
Add playthings to the cage, so they come into contact with each other less frequently and have different places to sleep if necessary.  Some great, inexpensive ideas include toilet paper rolls, paper towel rolls, empty tissue boxes without the plastic, toys made from popsicle sticks and hot glue, and other easy-to-make hides and toys.

Scatter food in different places around the cage, so no one mouse can get defensive of the resources.  Mice love digging around and foraging for food, anyways, and this way they don't have to go to the same place to eat.  Two water bottles on opposite sides of a 4 foot cage can also be highly beneficial - both to you and to them.  You will have to refill their water less, and they will have two places to drink.

You can also pull out the bullies for a little while, let the others take control of the cage for a few days, and then reintroduce the older mice once the others have become established again.  I'd try this as a last resort, however, because each time you reintroduce them they will have to readjust their pecking order and there will be standoffs for a couple of days.

I hope this helps, but like I said - if there are any serious injuries or real bites you will have to separate them, even if only to let the injured mouse heal.  Squeaks mean a mouse is scared, not necessarily that it's being injured, so you should keep a very close eye on their coats for any balding spots or scabs, and on their ears and tails for nips.  If one particular mouse starts to slow down and become lethargic it will also need to be separated - sometimes the stress alone can cause a mouse to get sick and you'll need to nurse it back to health away from its aggressors.

Best of luck!
-Tam