Our 20-month-old Buff Orpington hen has refused to move from her nest box for 3 days. She has always been an egg-a-day layer. There is no egg under her, and we've forced her out into the run a few times, only to have to peck around for a while, then return to the nest box. We checked her vent (not way "up in there," but we took a good look)---it looks perfectly normal and clean. All the other hens (3 Buffs, 4 Speckled Sussex, 2 Leghorns, and 3 Rhode Islands) are acting perfectly normal. I don't think she's been eating or drinking -- at least not when we're around. She has no signs of visible trauma or injury, although her legs have always been a little funny --- she walks with a much more pronounced strut than the others, but always has. Her poop yesterday, when we forced her into the run, was runny -- but didn't look like anything to be alarmed about. I called the organic farmer who sold us to her, and he'd never had any egg-bound chickens. We thought that was the issue, but her vent looks perfectly normal. But STILL --- it's been 3 days, and she just wants to lay there, and she hasn't laid an egg. Doesn't that mean she's egg-bound? We're not sure what to do. Any help/ideas/insights you can offer are MUCH appreciated. THANK YOU!!!