Rats fighting. Help!

[RattoPazzo]

So, my two femail rats have started to fight and one of them in getting bitten...
I've had them for about 7 months and they'r now 10 months old; they are littermates. A while back I started notecing that theire play fights had become somewhat more intense but, seeng as they where still cuddeling and grooming each other, I did not worry to much. Now its getting to the point where I started to find bitemarks on one of them; not deep one more like scratch deep. The thing is that the one who is getting bitten can be quite annoing to the other, insisting on things even after her sister has told her of. Interestingly, she is also more shy and, I'm assumig, the submissive. One other thing is that thay seam to fight like that only dourig freeroam. I'm at a loss, I don't think it so sevire that I have to separate but I am gatting quite worrid.
Any feadbeck is greatly appriciated
thenks

 

[Big Schpog]

I am so sorry you are having problems with your bitchy girls. LOL If there are wounds that are bleeding you will have to separate them. If it's just a couple of nips then it's not an issue if they're still sleeping and grooming together. Can you provide a pic of the injuries?

 

[RattoPazzo]

I don't have pictures, the wounds have since heald over and thankfully ther hasen't been any new fights. I never did see her bleed, I just noticed the small scabs on the back after.
One thing I forgot to mention before is that almost at the same time as the figts startet, I had to treat them for some suspicus sneezes with a nebulizer... maby they noticed before me that thay were getting sick and that sresst them out... I really hope so, because since then thay have been getting along great
thanks again

 

[RattoPazzo]

So tonight Tamira, the one who was biting my other rat, jumped her agin while they were eating. Nothing serius this time, but Nifti, the one who got jumped, did act strangely all night. Now thay are in their sptnik, in a rat pile, as if nothing happend. I'm lost, I don't think separating them will do any good and I don't know if putting them in a small cage makes sense since I know that thay spend the whole day sleaping thogether.
The thing that makes me uneasy is that I can't figure out why this is happenig... is it hormones? are they still sick? is it just "teenager stuff"? are thay lonley and don't konw where how to express it? are they bored?
sorry for the many questions but I really don't know what to thick or do