So I have a basically two part question:

The first is I have noticed progressively the male has been attacking the female more and more. It was usually over food, but tonight was really bad. She would be in her corner hiding or walking on the opposite side of the cage and he would grab and launch across the cage to attack her. No balling, but she would retaliate a little. I took her out and poor thing was shaken up. But this kind of thing has been getting worst and worst and this last one went on for 10 min. There is two+ apple chunks on the bottom (she likes to take her food and hid because of him) and he won't let her get near one.

The second leads back to the female. I have noticed her forehead seems to have thinned out of fur. And I don't mean a patch, like from her nose to the horizon of where her ears start all seems to have been thinned. Should I be worried?

How long have they been together? I would def separate them for a little while.

It would be good for us to know how long they've been together.

There are things you can do about the food fighting, the fact that she is trying to hoard is definitely a sign of trouble there. You mentioned, "two apple pieces". What diet are they on? Some of the problem may be due to an insufficient diet or not enough foods. If it isn't that, separate feeding stations and treats hidden around the cage would give her a better chance. How big is their cage?

Over grooming is what you are noticing on her face. This is definitely an indication of stress/distress.

I would suggest taking them both in for a vet check. Either of them may have a hidden illness (one that hasn't taken them down enough for you to notice yet, and when they do go down it is often too late). She could be ill and he is reacting to that...or he could be and is acting out with this aggression.

They have been together for almost three years now, and not once have they had an issue this bad. They have bickered but not continuous through the night. I have her on the HPW diet, I generally give them little more then two teaspoons of fruits and veggies just to be sure. She is the chubbier of the two, but he does get his fair share. Its just weird cause he will go after her no matter where in the cage and she just takes it. What throws me off the most is she takes it cause she usually throws her weight around against him when he miss behaves.

That narrows it down, thank you. A well bonded pair with a good diet.

I would definitely be most concerned that there is a health related issue going on. Especially since she is not "throwing her weight around" to balance things out as she normally does. They can definitely sense illnesses in each other and will react in behavior that would be consistent with a colony pushing out a sick member for the survival of the colony. I've also seen the opposite. A cage mate becoming very protective of a sick mate.

Personality changes are something that very often is a first clue to an underlying health issue. I'd say the check up is the best plan of action and go from there.

Thank you, calling the vet now! haha

Perfect. Keep everyone updated on what, if anything, they find or suggest.

Best of luck!

Sorry for the late reply, school caught up. After visit to the vet, they said nothing seems wrong with her. She has no visible wounds and is a very plumb little girl (healthy range, of course). The only thing the vet said it could be is one of two things: either the boy is rejecting is cage mate or he is reclaiming dominance due to them closing in maturity of age. The second one makes sense cause she has always been a passive one while he has always been a skittish little boy, so he might be trying to claim dominance through fighting over size. She recommended me separating them, and I haven't had the chance. However, I have noticed it decreasing little bit. Got bad last night, but it was the worst over the past four or so days. I was going tomorrow to get a panel to separate them in the cage. Her fur on her head has started to thicken so what ever was causing that is better. They did take a feces test on her just in case, but haven't heard back just yet. Any thoughts on that?

So I separated them but the boy seems to be hissy fit. He is by himself and runs around hissing as if he still is mad. Any rhyme or reason why?