Fervent Hoarding

Question
I have two female rats that are about 7 months old.  They were obtained from the same breeder, not sisters but born several days apart and have been familiar with each other since then.  THey've lived together since they were 5 weeks old and I've never had any problem with them getting along.  However on Monday I introduced a new lab block to them, which they hoarded all night long.  This isn't completely unfamiliar, the one girl almost always hoards a little of their food however in this instance, they went for hours, one hiding it one place and the other hiding it another then each trying to steal the other's stash.  This caused some scuffles, which also isn't completely unfamiliar, a few months ago they did quarrel and scuffle often and I followed the general no blood-no foul principle. Now whenever I put new food in they just hoard this and seem to spend a lot of time fighting once more.  Before when they fought there would be the occasional squeak, but there have been several instances in these recent tiffs where one of them will have a higher pitched, more drawn out squeak.  The more dominant rat of the two is the one who typically hides a little food and she's the one who started the hoarding session on Monday.  The less dominant lady is acting just a little weird.  She's just as friendly if I get her out of the cage, but usually all I have to do is start talking to them and they're ready to come out.  Since they started scuffling all the time (Monday) I can go up, open their cage and get the other rat out and the less dominant rat is still hiding somewhere or other.  She also seems to perhaps be sore, interactions that are very typical between her and I (sometimes as simple as just picking her up) will cause a little squeak. Even the more dominant rat crawling into their tube-hammock sometimes causes a squeak or two. PRior to Monday they very rarely fought, there was a period in June-July where as I'd said before they were scuffling often, but I found information that says they're more likely to do this as teenagers and it will phase out, so I had assumed that is what happened.  I'm mostly concerned as to whether I should separate them or if there are any clues as to what might be causing their fights.

Answer
Hi there

Rats do fight, but its not as common in females. Males sometimes start to scrap more as they near puberty, which is anywhere from 6 to 9 months of age. They do this to keep their pecking order in check. My boys are always tumbling around and I have had them since they were 3 weeks old and they are now four months. Usually when one squeaks, the other one stops. I have to ask you though, are you keeping food down at all times for your rats or do you feed them at certain times?  I always suggest to keep dry food down at all times for your rats no matter what. Rats very rarely over eat because they know they cannot vomit. The fresh fruits and veggies of course cannot be kept down at all times but I suggest of course a high quality lab block that is low in protein be on hand at all times and also a rat mix that consists of high quality dog foods such as wellness brand dog food (as an example) along with sugar free or low sugar/low sodium cereals such as puffed wheat and puffed rice, rice chex, even cheerios in the mix are ok.  Dry oatmeal flakes and total cereal can be added to make a nice mix for the rats to be left in a generous size dish so it can be full all the time for the girls. Chances are you are already on top of this but if not, let me know so I can pin point the reason for hoarding further. Also, how often do they come out to play and what is their play time like and what is their play area like?