are my gerbils fighting?

Question
i have two female gerbils. one black one white, there are both the same age and i bought them at the same time from the same place.

i tend to her squeaking every now and then, but when i look over it just looks like there playing.
i have found what looks likes marks on the white one. but she seems to be the more dominant then the other.
they both seem to get along fine most of the time
I'm just worried something is going to turn out bad

Answer
Sometimes gerbils will groom each other and sometimes pull out tuffs of hair. The best thing to do is what you are doing now and that is monitor them. I generally seperate animals when I notice them truly fighting. The first time I see them in a ball I seperate them. Generally gerbils will look like a ball when they are fighting and you will know when they start fighting. The minute you see any type of blood that's when you should seperate for good then. I generally try not to wait to see blood though.