We have had chickens for around 6 years now. In the city, free-range on the farm and in a run/coop on a farm. I have never experienced this before! I have 2 mamas taking care of 6 babies together (this is common for us). One mama has been standing hunkered down and not moving AT ALL (just her eyes are blinking and kind of looking around, but mostly looking sideways and upward). She's making this very low growling purring sort of sound. The other mama is about 3-4 feet from her and has all the babies huddled in the corner and is very quiet and still. These babies are about a month old and usually very, very busy! They are all laying in a pile and still and quiet! This has been going on for about 15-20 mins. All of the other chickens are sticking close by the back door and are pretty quiet as well. I've been sitting out back on the step watching and listening and haven't seen or heard anything different. She is absolutely not going to move from her position either! We are in the city with these chickens. I'm assuming that she knows something I don't. Any ideas? Amy J.