My 6-year-old sex link hen looks to be the same weight and she is not missing feathers. We have recently lost her flock mates so she is alone for the time being (I am working on getting her a friend ASAP). I recently noticed that she will occasionally let out what sounds like a scream in a voice that I have never heard her use before. She is also tending to stay on her nest (I haven't found broody feathers) but she has been eating and drinking (it is about 85 degrees F outside and quite humid). When she was in her run earlier today I noticed that she frequently shook out her feathers. I don't know if this is related but her eggshells have been thinner lately. She has been exhibiting these symptoms for about 4 days now. I did not find any signs of trauma. The only things I can think of that may have instigated these behaviors is the intense heat and humidity as well as her recent status as an only chicken (planning to change that). She has been eating her regular table scraps and standard chicken feed with some cracked corn every day and has been drinking water. Her feces are a bit runny but nothing unexpected for her. I have not administered any treatment but I am planning on putting some electrolytes in her water and giving her fresh bedding. Her current bedding is pine shavings and pine needles in her nest. I plan on treating her myself if at all possible. Thank you for any insight you can give me!