how early can roos act like roos?

[Saerasx]

might be a silly question but the thought popped into my head this morning. one of my chicks (a few days old) figured out how to hop onto the Brinsea and was proudly chirping, VERY loudly I might add

 

[MonkeyRoo]

Well, I have two crowing at 6 weeks..... One of them I knew was a rooster at 3-4 weeks. He had no fear! From jumping in my hand to running around the box and running over the others. The other I swore was a hen, so docile from day one! Is your chick sexed? Just wondering if you know what it is and are just waiting for the "little man" traits to show up or if it is unknown and you might have a roo in the bunch....

 

[Saerasx]

They should all be female but I have a hunch about one...