UPDATE: Chicks are now 5 weeks and 5 days old. They are still in the brooder, due to the unusually chilly temps we've been experiencing this week. I'm weaning them of the heater, so they can move to their coop permanently as soon as the weather cooperates. Anyway, I went to turn on the light and check on them this morning and Mystery let out the weakest, raspiest and squeakiest little crow! It scared the little pullets all to death and they all ran and huddled into the corner in terror! I said to him, "What was THAT?!" Mystery just stood there and looked at me, as if to say, "I don't know, it just popped out."