I have 2 brs that were supposed to be pullets; got them at about 14 weeks. They are now roughly 18 weeks. Thought one of them laid its 1st egg yesterday, but wake up this morning to hear CROWING...tried to sit & watch to see which one was doing it, but of course they clammed up! How do I tell by looking at the physical characteristics if one is a roo? If I need to take pics, what do I take them of (head, feet, whole chicken)?