Last week I got two kittens from the humane society. They are 10 and 11 weeks old and both females. I kept them in separate rooms all week and pulled them out one day to put one in the kennel and the other outside to sniff each other and watch. They only pawed at each other and sniffed around.

Today I let them both out to introduce them. I held and played with one (the more rambunctious one) while the other went free. They were curious and started pawing at each other and then began biting each other's faces. There was no hissing or meowing but they were biting each other at the same time fairly hard. I separated them again and ended the interaction. I did this two times today with the same reaction. Is it normal for them to bite each other like that and paw? I think they're trying to establish dominance but I'm not sure. Should I always intervene? What should I expect when introducing cats?