Yep, that's it......they change from peeping noises to clucking noises around 3 months or if your like me....lots of crowing noises. In my first round I raised 5 out of 7 roosters and couldn't keep them. Have fun with your chickies. Bock! Bock!
I though once they are layers they are hens....cause I have a girl hatching a batch of eggs right this minute who is only 7 months and a few days old. I think if she is a mama she certainly should have earned "hen"....