This particular hen has been acting "funny" for a while. . .just a general malaise. For a while she wasn't going to the upper perches with the rest of the girls when it's bedtime. . .she was staying on the lower perch with the rooster. After a while, she resumed joining the ladies on the upper perches. Last night, she stayed in a laying box which is directly on the floor and tonight when I went out to close them up, she wasn't even in the coop with the rest, but rather under the coop. The area under the coop isn't readily accessible, and when I tried to herd her out with a stick, I literally had to push her out from under the coop. I'd put the stick under her butt, she'd walk a few steps and stop, and I would have to prod her again. Once out from under, she went up the ramp under her own steam without anymore prodding. No limping or dizziness; she just moved very slowly. Once inside, she went into a laying box. I picked her up and looked her over. Her nose and mouth are clear, no growths on her tongue or anywhere on her body. Her eyes are clear and her comb is red. No facial swelling. Her feathers look healthy. Her crop is not enlarged and I feel no egg inside her belly. Her belly, however, does seem a little thin, like she hasn't been eating. I haven't taken notice of her droppings so I can't say anything there, but her vent is clean. This has been going on for a week or ten days and I see no symptoms in the 8 other hens or the rooster. Any ideas?