One of my hen is sitting in nesting box forever. I took her out but she goes back in. I checked her vent but looks normal and she comes out from box and eat and drink sometime. She looks not suffering from some pain and I don't feel egg around her vent. I took a egg from nesting box next from her box and she was hissing to me. No eggs from her for 2days. I'm guessing she is in broody mood but I want to make sure she is not egg binding. What do you think??