Aggression problem...

by MousieMomma Mon 14 Sep 2020, 12:48 am

So about a month ago I got 4 mice (all female) from PetCo (yeah I know, bad idea, but when I got them I didn't know much about mouse genes and reliable breeders). One died unexpectedly just this past week so now I'm down to 3.

I've noticed that the biggest mouse–Storm–has been particularly aggressive to the smallest mouse–Cinderellie–whereas she doesn't have any beef with the other mouse–Sif. At the moment, it's minor (chasing her, grabbing her back, and biting at her neck every once in a while, I'd say less than once a day), but I'm still very worried about it. I fear that it might get worse over time and may result in something unspeakable. It doesn't happen because of food because I scatter feed, and I'm certain that it doesn't have to do with cage space as I have a 700 square inch bin cage that has plenty of space for the three of them. This has been happening since day one, when they had a much smaller cage, and hasn't stopped since...

What can I do to stop this behavior?

Edit: I think that both Sif and Storm are becoming aggressive towards Cinderellie. I've decided to put Cinderellie in her own separate cage for the night, and until we figure something out.

by Molly_mouse Mon 14 Sep 2020, 9:59 pm

Hi!!
I’ve never had to deal with mouse aggression myself, so take everything I say with a grain of salt, it’s only what I’ve heard. The aggression could be over something like a favorite toy, or only having one wheel or one water source and wanting to use them at the same time. If you don’t already, I would have two wheels and two water bowls/bottles in their cage at all times. Female mice always have one that is dominant, but sometimes a dominant mouse can turn into a bully mouse. I’d say do some more research as I don’t know a lot - even YouTube can have great information. If this continues, you may have to House Storm alone. Even though female mice are social, some just aren’t fit for groups and unfortunately they have to live without the company of any other mice. In the future I would recommend instead taking the aggressive mice and not Cinderellie for a time out. This can make the aggressive mice feel as if they’ve won and that can only encourage the behavior. I wish I knew more but I hope this helps, good luck!! I know it can be super frustrating to have things go wrong with your pets, and have it seem like nothing you do works, even if you sink quite a bit of money and effort into it. I commend you for being an amazing mouse parent and I hope you get it figured out soon. Sometimes things just don’t go your way, and it can be really frustrating.

Edit:
I was perusing this site when I came across another forum that had some good information on this topic, and I thought if you hadn’t found it already it might be of use to you.
https://www.petmousefanciers.com/t2431-3-female-mice-and-sudden-aggression-problem?highlight=Aggression
I would recommend reading through the whole thing, especially the second page but in short, months of trying to solve cage aggression was solved simply by taking out the wheel. One mouse can become over protective of one item, so I would recommend seeing if your mice have an item like that and trying some of the strategies described in the other forum.

Aggression problem...

Aggression problem...

Re: Aggression problem...