I had 7 RIR packing peanuts come with my 12 Barr Rock pullets when they were shipped from Ideal. They must have been from straight run as some are roosters and some are pullets. They are 12 weeks old now. My problem is how can I tell for sure which ones are the pullets? I thought I could tell by their combs as the roosters would have bigger combs. Two, I know are roosters as they have larger red combs and are crowing. But, one that I thought was a pullet was trying to crow this morning. Is there a sure fire way to tell which ones are roosters? I am going to cull the roosters away before they start laying and want to be sure I get all of them.