Four days ago I rescued 2 hens from our local humane society. They treated them for mites, but otherwise in very good shape. They are in quarantine from the rest of my chickens. I have had chickens for almost 10 years and have never seen these 2 behaviors so I would appreciate your input. They appear to be about 1 year old of mixed RIR or Orpington variety. They are thin. 1. They do not roost in their coop,. They do not go inside when it gets dark. They are in a covered run that is attached to their coop.I have had to physically place them inside the coop and close them in every night. Is this normal? 2. Yesterday morning I found one of them lying down inside the coop. She could not stand nor could she walk. No broken bones or injuries I could observe. I separated her in a med size crate and checked on her periodically throughout the day. She was very hungry but still could not stand or walk. This morning, she was up and about, walking normally and appeared perfectly healthy. I did notice she laid an egg in the crate. I still have her seperated. Why do you think she could not stand or walk? Any input as to these behaviors would be appreciated. These are my first adult rescue hens so I am a newbie with hens I have not raised from chicks. Thank you.