I am clearly a newbie to having chickens, and today when I took 2 of my 4 out to play, they did the normal scratching, pecking, eating... And after a while they stood perfectly still and started making this other noise. They both did it, like a conversation, but neither moved a muscle. I tried to get it on video, but they were not completely cooperative. After several minutes, they just sat. Eventually, (seemed like an eternity) they got up and started acting normal again. What was that? Scared chickens? Tired chickens?