I am thrown for a loop after what my chickens just did. I have 5 Rhode Island Reds, and in the four months we have had them, I have not seen anything like this. I am hoping someone can give me a clue what this is all about. My girls were just scratching around in the yard like normal. Four of them usually hang together, and one will just do her own thing. So my four girls had just walked out of the garden onto the patio, with Bonnie ahead and three others behind. All of a sudden, they just STOPPED and STARED all in the same direction, looking toward the corner of the yard, and all started making this loud, "purring" noise that I have never heard them make. (I looked but didn't see any kind of animal in that corner, nothing that got my attention). Meanwhile, the 5th chicken came running across the yard to join the group. When she got to the patio, she just stopped and stared, also, and she also seemed to be making the purring noise. At the same time, I could hear a plane flew overhead, but this was not out of the ordinary and was not particularly loud, either. so I had no clue if anything could be provoking them. This was so strange. They held their pose for a solid 4+ minutes. Normally they scratch and walk around doing whatever, but ALL 5 OF THEM stayed motionless, together, doing this purring noise. It was loud and a constant hum, even though normally they all make slightly different sounds amongst each other. Bonnie was in front and seemed to be leading the group, and from where I stood on the deck I could see when she purred her bottom feathers would stick out, like she was flexing her butt muscles. Yes, really! Then at some point, Bonnie did a quick shake of the head and I saw her blink, and I guess the spell was over. They all looked around and got back to looking for bugs and stuff. This was so bizarre. I knew I was getting mosquito bites but I couldn't stop watching because it was just unreal. I haven't posted anything yet on Backyard Chickens but I have got to know what this was all about! Someone, please help!