Constant fighting

Hello !!

I need some advices because I cannot stand the situation anymore, it is breaking my heart !
I do not know if that is normal but my girls are fighting ALL the time, EVERYWHERE and for "no reason"... for over 3 months !
They are 5 months and a half, almost adults, and still there is no stable hierarchy established : they both eat at the same time and in the same plate, and when they fight the dominant is changing from week to week...
They are sisters so they are almost the same size and weight and they have very similar personalities... which might no help in defining a dominant...

They have a guineapig-ferret joint cage (2 cages joint together so about 75 x 45 x 120 cm of space), I let them out in my bedroom for at least 2h30 per day (very busy working days...) and I train them twice a day for tricks...
I act exactly the same with both, I am not suspecting any jealousy...
I never intervent in the fights, but I can't help looking when they scream (come on, they are my babies...) but I never talk or move my body ! It seems that my look freezes them (they give me a look back)...
They never injured each other and always end sleeping together, but it is so irritating when they chase each other around or jump on each other... sometimes I find it quite violent...

I am a calm, deeply non-violent person so this situation is really bad for me... I never had rats before and all the ones I saw (from friends) were peaceful and never fought...

How often do your rats fight ?
What are normal fights ?
What should I do ? I was thinking of (may be) adopting a third girl with a different personality and physic (may be an older one)... what do you think ?

Thank you so much in advance for helping !

This sounds like normal behaviour. A rats scream is VERY different to a squeak of distress or surprise.
If they are protesting or surprised it's usually a short series of bursts, think a squeaky wheel on a bike.
The behaviour sounds a lot like play or basic dominance. The standing/stopping and staring is typical of dominance interactions, it's what changes them playing around to a real dominance interaction.

Some rats are squeakers, all our current ones are.
Meaning that the little communication noises they make are in our hearing range, when a lot of their vocal communication is usually undetectable for us. They may sound pained or worry-some to new owners, but it is generally just them saying 'get off me' to an overactive sibling. We were nervous of these when we first got our rats, but think of it as them talking to each other, instead of screaming, and you'll soon learn to contextualise the sounds with their behaviours.

They will chase each other regularly, and groom for dominance. Air boxing is also common.
Does are apparently much higher energy than bucks, so this may go on longer we would experience with our bucks. We have a few people on the forum that can be more specific about doe behaviour, but this seems completely normal for rats, especially at this stage where they start really getting into vying for dominance.

And to let you know what a real panic sound is like, it's surprisingly loud and very high pitched. It will start as a worry sound but within a second will become a near constant, significantly louder squeak. These can happen in general play (due to one of them backing into a corner and feeling trapped, so panicking) so in those cases it lasts about a second or two until the rat gets away and feels safer.
Since they are living together and so friendly as you describe, and especially as no blood was spilled, this seems to be their habits and attitudes. And when you met your friends rats they were probably too interested in the potential new treat dispenser to think about squabbling

Thank you so much for your response, it is reassuring
I looked for videos of rat screams and, indeed, it sounds very different from what mine do !

Thanks again !

What Tribble said!If there are no injuries and they sleep together i would not be worried at all

Girls in particular can be real drama queens! I wouldn't worry - it sounds pretty normal - you'd swear world war 3 was breaking out here sometimes!

xx

Lol! It sounds a bit mad here at times with the girls going at it like mad - all pretty harmless 'your cornflake is bigger than my cornflake' and the odd one who wants all the cornflakes kind of stuff.

It is generally about cornflakes here too XD

Hahaha well I would have understood for cornflakes or any toy acquisition but most of their fights are "free violence" : they meet to a point and fight... well it seems to become a bit better now... who knows why... they have bad mood periods I guess...
I know they are good drama queens because when I stop them before they do something wrong (like destroying my bed sheet) they scream at me, but they never do so when they were not intending to do something forbiden, THEY KNOW! Kunda is the best at that!