O. clowns fighting?

[johng723]

I have two Ocellaris clown fish that have been in my tank for about 2 months now, and there is one that is noticeably bigger than the other. They are both around 1 1/4- 1 1/2 inches, so I figure they're still young. They just started fighting tonight where they were locking mouthes and nipping each other. Should I be worried? I thought I had seen them decide their pecking order when I first got them since the smaller one would always do that seizure dance when the bigger one chased it. Is this normal?