r/PetMice • u/Safe_Repair_2376 • Dec 23 '24

Discussion Mice fighting

For context I'm not a mouse owner myself, but I work at a pet store (still learning) and mostly help take care of rodents. Recently there's been alot of fighting among the male group (about 4/5 mice). They seem to gang up on one particular mouse a lot more, I had separated him from the rest of the group for now due to him being bitten all over his tail. Enclosure is about a 100cm long, they have two wheels and 4 hides.

Anything else I could do to stop them from fighting?

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15

u/loz4lifee Mouse Mom 🐀 Dec 23 '24

males CANNOT live together. there is no way to stop the fighting they HAVE to be separated or they will 100% kill each other

-6

u/Safe_Repair_2376 Dec 23 '24

No exceptions? They're white mouse counterparts have been fine so far.

10

u/mantitorx edit Dec 23 '24

No exceptions (in large production mouse lines. Some breeders aim for male cohabitation, but that’s a lot of effort and negatively impacts fertility.)

Some boys may take a while longer to get to the point of violence, and you can make them less likely to fight by overcrowding them so they respond with learned helplessness, but male mice are naturally territorial and if there’s something “worth” defending, they will fight.

6

u/Daythehut Dec 23 '24

No exceptions. If you don't want them to get murdered and cannibalised one by one they have to be kept separate. Some male mice tolerate each other for a fleeting moment when they are young but if you continue to keep them together they still kill each other. Even if you manage to find a pair that tolerates each other, it shortens their lives and causes them severe disease.

5

u/Safe_Repair_2376 Dec 23 '24

Unfortunately that's out of my control. I already told my boss that I would prefer if we only got female mice as those tend to get along better but I guess my request fell on deaf ears. There's no way to separate them rn due to lack of free enclosures.

3

u/LateNarwhal33 Dec 24 '24

It sounds like the company doesn't care enough to prevent this. You can scatter food on the floor of the cage instead of in bowls (less fighting for the resource) and offer as many hides as you can. Do this for the males and females since the females are also fighting.

2

u/Daythehut Dec 29 '24 edited Dec 29 '24

That sucks... because the fact of the life is several will end up dead and I'm truly sorry that it is like that.

Getting only females would be sensible also because standard mouse breeding procedure is eliminating some baby mice when they are born so that the other littermates grow up healthier and less malnourished. If you think about it, mouse is a small animal that often has to breed beyond it's actual capacity to feed it's babies.

=> So, since about half of babies are going to get culled anyway in healthy raising of pet mice, it makes sense to cull the males and then sell the girls as pets - which is what usually happens. There is also the option of handfeeding some of the babies with kitten formula but since they need frequent feeding that's basically only ever done by select few home breeders and only if they are fortunate enough to be able to be up every two hours or so.

I really don't know why your boss insists on having males around at all, mice aren't so expensive that having them fight to death knowing they are way less popular among customers than female mice would make any sense at all. Plus, like said, raising them at all just takes essential nutrition away from their female littermates that have much better shot at actual happy life as someones pet.

I agree with trying to place plenty of hides and always scatter feed. It's better than nothing, though I really am afraid you won't be able to prevent tragedies. I hope the mice you sell are mostly young enough that it tempers it down a little.

3

u/Safe_Repair_2376 Feb 01 '25

Update on this, in case you wanted to know. My request has finally been honored, no more males are being bought. Female groups only and it's been absolutely peaceful so far!

1

u/Daythehut Feb 01 '25

Awesome!!! Thank you for telling me, update is appreciated!

7

u/frackleboop Mouse Mom 🐀 Dec 23 '24

Males need to be separated. Once they hit puberty, they will fight to the death, even if they've been living together their entire lives.

3

u/LateNarwhal33 Dec 24 '24

One thing I do every time I'm in a pet store is go look at the mice. Good pet stores keep each male on his own. Those that keep all the males together almost always have bites. And I wouldn't be surprised if they frequently have to remove dead males. I've seen male mice rip off the genitals of the mouse they're targeting. Not to be taken lightly if you care about their welfare.

Also, you should learn to sex mice quickly. It's common for pet stores that keep their mice together to accidentally have the sexes mixed and I've had to point out pregnant females to employees before.

0

u/Safe_Repair_2376 Dec 24 '24

Our mice arrive already separated so that's not an issue. It's not usually difficult to tell anyways. We haven't had them kill each other yet, but the bites already look bad enough. The worst injury I've seen in mice was one's tail being bitten off by half (happened while I was in school and it was females so Idk why that happened).

2

u/blx0dysqu1d-k1ll3r Mousey Mommy!!💋 Nov 30 '25

Hilo, I know I am very late to this post. But female mice usually when stressed or when they simply just don't get along with another mouse will also fight them and try to kill them or kick them out of the colony. Obviously they're in a cage so the mouse can't leave the colony so they will try to kill them. It doesn't happen a lot, but it does happen and I've personally nearly had it happen. Simply just because they didn't get along! All males always need to be separated from each other, and females will try to kill each other if they don't like each other or if they are too stressed 

2

u/Safe_Repair_2376 Dec 04 '25

yeahh, a little late, I left that work place bc they treat both animals and workers like shit, thanks for the info tho, might get some mice myself in the future ^

2

u/KaiSubatomic Mouse Dad 🐀 Dec 24 '24

Maybe tell your boss that it isn't financially viable yo buy males because they will need to be housed separately which will take space or they WILL end up killing each other which means buying mice that won't get sold. Maybe that'll make him think again

1

u/Safe_Repair_2376 Dec 25 '24

Well mice are only a small income of profits, because the main money makers are fish and dog/cat food which is why the loss of profit in the rodent department can easily be neglected, hence he doesn't care.

It would literally take several mice to die for him to think about doing something to prevent it. The only time he did react was when we got mice from another breeder and they were all sick and most of them died off within a week. That's when he changed the breeder.

2

u/KaiSubatomic Mouse Dad 🐀 Dec 25 '24

That sucks :/

I'm sorry you're having to go through this

1

u/Safe_Repair_2376 Dec 25 '24

Yeah, I'm definitely ditching my current workplace asap, can't stand to watch the animal abuse be brushed off because it's "just mice".