I think Mrs. Eggna is right about having other roos to compete against. We ended up with 3 roos, unintentionally (but now love having our boys). I think we had a little testosterone fest going on which is why they all started crowing so early. We had one trying to fight his 3 female brooder mates at 3 weeks! The girls were like..."What the???" He was trying to emulate the 7 week old roos in the next brooder (they were divided by a mesh panel).
I have heard of hens taking on roo characteristics. Waiting 6 months to know if you have a hen or a roo...dang!
I have heard of hens taking on roo characteristics. Waiting 6 months to know if you have a hen or a roo...dang!