I have three 5-week-old GSD/Husky mix puppies, and one of them, Kaya, is terrorizing her sisters. She tends to just pounce on them and grab them by their little heads, and just bite them and shake them, all the while they're just yelping and trying to get away. I was told to take her by her scruff and gently shake her when she does it, but it just seems to make her even more angry! She just growls and actually snarls at me! Her sisters are to the point where they are afraid to even play with her now. I have 11 other dogs, but have never had one with Kaya's kind of temperment. Is she just showing that she is the dominant one of the litter, and should I worry? Any suggestions would be much appreciated, but keep in mind she is barely 5 weeks old!