Ok, I dont really know how old they are or if they are related but I would say they are full grown alduts. They do fight little scubbles about food and the wheel but it is over very quickly and not violent at all. The violent fighting is very random and not over anything particular but there is blood, alot of it. The big one, Pepper always goes for the tail of Cotton who is also blind due to Cateracts. Her tail is in a bad way which is why I am seeking advice before putting them back together. They have a lot of room to play, there is one standard size rat cage and my partner built a massive run for them that the cage attaches to via a tube. He can fit in the run to give you an idea of the size. There are alot of sticks and tubes in there as well as a wheel. I always put in fresh hay and food is always there.
At the moment one is in the run and the other in the cage. I swap them around every day but I am gonne start doing it every other day now because when I do swap them they become unsettled again.
My partner reckons that Pepper may be mentally disturbed as she is very unfriendly and legs it when ever you go near the cage.
I hope I have put enough in xx