My almost 1 year old black sex linked hen keeps returning to a nesting box. She is normal weight and doesn’t appear to be losing any. I took her out yesterday to try and inspect her and she got up and ran around the yard like normal. She was eating things in the yard and took a dust bath. She has on and off open-mouthed raspy, almost gurgling sounds when she breathes. She does not appear to have anything wrong with her nose or eyes. When she came out, her poop looked very hard and sort of undigested, it was very green. She has come out to eat a few times and perch on the roost but keeps returning to the nesting box. My other hens have pecked her head bald. None of my other hens have similar symptoms.