Relatively new to raising chickens and have a 1 yo rir that's been behaving rather strangely the last 3-4 days. I thought at first she was brooding as she would not leave the nesting box however, when I'd remove her from the box (she's sitting on golf balls) she walks around kind of crouched down with her feathers all poofed out making a weird, low growling noise. She will eat and go out for a bit but make a mad dash back to the hen house. I noticed the other hens pecking at her as well. All my birds are free range except at night and have two acres to roam. She's only eating/drinking when i force her from the hen house. Poop looks normal. What is going on with this bird?