We just got two new breeders (Cow and Leia for future reference - the original girl mice are Sapphire and Newn) and Sapphire, is picking on them, especcially Cow.
Okay, originally when we put the new girls in the cage, we noticed they were being picked on, so we moved the three original mice out into a separate cage for awhile, to let the new ones kind of make the new place their home or something (like we do when switching around our two males.) Unfortunately, when we put them back Sapphire started right back up bullying again - she bit Cow's tail in a couple of places.
We've moved Sapphire to a cardboard box for the moment, the one the new mice came in - with her own bedding and water of course - but we need a more permanent solution.
I'm pretty sure that Sapphire is pregnant, so could that be what's causing this behavior? And if not, what can we do about it? We have two separate cages, one for the females and a male, and one for the other male, and then we switch them once a week. Could we keep some of the females in one cage and some in the other maybe?
I'd appreciate any input anyone has, thank you.

__________________
-Jennie the petsitter

I'm sorry I don't have an answer for you.
I know things about rats but not mice....sorry
Good luck finding your answers

By the way...no cardboard box will stop a mouse from chewing their way out. You need to find a suitable container that she can't chew out of.

The bad news is; it's going to happen with mice. Rats are more sociable than mice and will accept strangers. With all of our mice we start a breeding colony with about 5 or 6 females with one male while they are still young. After which we never introduce another female because the original females will recognize a strange scent and they will pick on the newcomer, usually to the point of killing them.

__________________
Fran
January 9, 1940 - June 1, 2006 (R.I.P)

Sapphire no! Bad girl! Rrrr, naughty mouse. Hmm, try doing what we did with the rats when I got Pooga. Clean out the cage really good and set it up again. Then put the two new mice in there and keep Sapph and ______ in a seperate cage. Not a box! I got plenty of spare cages in the closet and if you don't like those there should be more outside on that sink on the side of the house. Ok, after the new mice have been in the cage for a day or two, reintroduce Sapph and ______ to the cage. Hopefully it will work. The idea is that the cage will be dominated by the scent of the new mice and Sapphire and _____ will be in THEIR territory, so they won't beat them up. It might work. Works with the rats anyway. Oh, and you don't have to worry about Bear or Thor beating them up. They've got other things on mind If it still doesn't work, then you can keep Thor and 2 girls in one cage, and Bear and 2 other girls in a different cage.

Oh, and "Newn"s real name is _____. No, there's no dirty word that goes there, the blank space is her name. Jennie just calls her Newn cause she likes to be difficult.

__________________
+5 bonus points to whoever finds me a job!

"Eagles may soar, but weasels don't get sucked into jet engines." - John Benfield

Yeah, we tried that already, putting them in separate cages, and Sapphire just started up again. She seems to hate Cow more than Leia, too. So I guess we'll just separate them permanently, in the two different cages. That seems to be the only option.
Thank you for your replies. Especcially Jem - I ran over to check on her, and luckily she's still her, because she had started work on two holes. Whew. Luckily neither is big enough for her to squeeze through - I'm going to right now and put her in Bear's cage before she has a chance to work on them again and escape.
Thanks again.

__________________
-Jennie the petsitter

Never mind! You know how I said that I think Sapphire is pregnant? Well, she had her babies while she was in that box! So now I can't move her, because I can't move them.
I duct-taped spare cardboard over the holes, but she can probably just chew new ones. Does anybody have any suggestions now? I'd really appreciate any ideas. Thanks.

__________________
-Jennie the petsitter

Is the box big? If you can, just set the whole box in a cage and cut a hole in the side or let her chew her way out.

__________________
+5 bonus points to whoever finds me a job!

"Eagles may soar, but weasels don't get sucked into jet engines." - John Benfield

Thanks. Did that. The problem is resolved, and we are never ever doing that again.
Thanks everybody. Especially Furryscaly, of course.

__________________
-Jennie the petsitter

lol, well now that that's fixed, Cow and Leia? I just gotta know why you picked those names. Oh, and what sizes are the two cages you put them in?

__________________
+5 bonus points to whoever finds me a job!

"Eagles may soar, but weasels don't get sucked into jet engines." - John Benfield

Cow, Leia, and Bear are are in the former 'extra male' cage. Sapph, Newn, and Thor are in the other cage. (So I guess we won't be switching the males around any more will we?)
Cow is white with black spots. I wanted to call her Domino, but it didn't fit. John wanted to call her Heifer. Then I decided on Vaca ('cow' in Spanish) but that didn't fit. So then it was Dalmatian, Dally for short. But John couldn't get 'Cow' out of his head. I'm not sure if Dalmatian is her real name and Cow is her nickname or what....
Then there's Leia. Her full name is 'Leia, the Crown Princess of Wales.' Don't ask me why, it just popped into my head.

__________________
-Jennie the petsitter