Pullet Acting Like a Roo?

[Gracefulspice]

I'm new at this chicken thing yet. Especially with my 5, 10 week olds. I'm questioning the behavior of the Buff Orp. She is much larger then the 2 RIR and 2 Jersey Giants. Also she seems to be the dominate one. I've seen her a few times run up to another and puff up her neck and stand real tall like, and kinda pounce in a way. The other will do the same behavior back at her however. Tonight I knelt down to get close to them and she ran infront of another that was coming to me to block her. Can this be normal behaivor for a 10 week old pullet, especially a Buff Orp. Or is it Rooster behavior? I know there's a pecking order and all but I've always heard of how docile Buff Orps are and it kinda surprised me.

I've included a pic of her when she was approx 9 weeks old.

 

[Whirlwind]

I think they are just estabilishing pecking order. I have 3 ten week olds. 1 pullet and 2 roo's and they all do this. I think the pullet does it the worst. She will even do this to me if I try to grab her.

I think she just wants to be the top chick.

Thought I might add she looks like a she to me.