I purchased 6 sexed chicks - 2 ISA browns, 2 Australorps & 2 Heritage Long Lays. They are 5 weeks old now. I'm highly suspicious that one HLL may be a boy because his legs are noticably thicker than the others ,he has a much wider space to grow a comb but nothing showing yet while all the others have tiny combs coming up and he's the most dominant. However, this morning, the youngest ISA brown looked like she was crowing at me but no sound came out and the HLL followed suit. Do boys 'practice' crowing before their voice comes in?