I have 17 pullets. A few are 11 weeks old and the rest are 10 weeks. They have definitely grown past the vocal "peep" stage, however, the sound I heard coming from two of my girls last week completely stunned me! I assure you, I am quite positive they are all female. None have spurs or the classic rooster comb on their forehead. But there was no mistaking the crisp sound of "cocka-doodle-doo" that morning, and every morning since! Is this something they will outgrow or will it disappear once I bring in a true rooster into the flock early next spring?