New hens! Help!

[colby bush]

I recently bought two buff orpingtons id say about 8 to 9 weeks old and are still chirping like baby's but have all feathers with a little fuz. How can I sex them? Also how and when should I put them with my blue cooper Maran rooster and 9 RIR hens?

 

[HighStreetCoop]

By 8-10 weeks the combs and wattles (esp the wattles) are MUCH larger on the cockerels than on the pullets.

This is my cockerel at 8 weeks.




Here he is again at 10 weeks.