Aggressive DBT! Please help…

Hi everyone, let me start out by saying how happy I am that I found this group…I’ve been reading over the posts and it appears we have a quite a collection on DBT veterans here. With that being said, I was wondering if someone could help me out. My wife and I are new to the game, having just recently added two members to the family, two Northern DBT’s (Maya and Mika), this January. They are currently in their juvenile stage (I think – about 4 inches) and recently have been having some issues. One day my wife and I came home and noticed that our smaller DBT (Mika), had a scab on her neck, under her chin. I was concerned but figured it might be some kind of natural shedding and figured it would heal itself. Then one day we noticed that while Mika was basking, Maya swam up over to the shore and tried to bite at her neck. I thought at the time that maybe Maya was simply picking at the loose skin hanging from Mika’s neck (I still did not want to believe that Maya could have done this to Mika). But then last week I saw something that really sealed the deal. Maya bit at Mika’s neck and locked on while Mika started frantically scrambling to get away. This really caught my attention and broke my wife’s heart because she wants to believe that they are best buddies… I read on Jonathan’s website that they sometimes nip at each other’s feet, but I never thought that they would be THIS aggressive towards each other. I think it might be that their tank is not big enough for the two of them. We ordered a 65 gallon tank two weeks ago knowing that they needed more space, but glasscages.com only delivers to the west coast once a month on the 27th. I didn’t know what else to do, so I separated them and put Maya (the biter) in a separate container, but not a tank. We are constantly changing the water for her to keep it warm and clean for lack of a better temporary habitat, at least until we get the big turtle tank. My question to the group is this: why would they attack each other? Has anyone encountered this behavior before? And finally, what is the best way to keep them separated, or should I say, what is the best temporary habitat that we can create for Maya until April 27th? Please respond ASAP with any answers or suggestions. Thank you. ~Andy