One of my hens is acting strange today. She was fine until this evening. They ate some corn cobs and pecked at some apples so nothing out of the ordinary. When I went out later she was in the corner of the coop yard. Standing there, but just staring. Not paying attention to the others walking/pecking around her or anything. It was almost like she couldn't walk or move. I got home at dusk and saw she had made it inside, but only barely. She is lying on the coop floor and is all "puffed up" looking with her butt in the air. I picked her up, and put her down and she took a few steps and there's nothing wrong with her legs. She's not lame in the least. It's like she just pauses. She made it back to her corner and is lying there again by herself. She always roosts with the others. She's going to be 3 yrs old soon. Could she be egg bound? I thought of that, but it doesn't explain why she's "freezing". It came on all of a sudden. Is she having a stroke or something? Any ideas?