My chicken Harle seems to be sick. I think it's a he, but don't quote me on that. Lately he's just been sitting in the corner of the coop not really interested in doing anything. His wings are droopy (not too uncommon for him, but I thought I'd throw that out there), one more so than the other. He seems to have trouble balancing when you pick him up, which is pretty common for him, but he seems worse than usual. Harle doesn't seem to be drinking much, and I kind of suspect he can't find the water dish. If I put water directly in front of him, he drinks. If I don't, he doesn't drink. He seems to have more energy directly after he drinks, and he will stand and walk a little bit (though he stands in a lopsided way, which isn't normal for him). The rest of his polish flock is leaving him behind to forage, and he won't join them. He sometimes goes outside the coop, but doesn't do much when he's out there except stand near the coop. He was perfectly fine about two weeks ago, but then we went out of town and he just doesn't seem to be the same. I did give him a quick look over, and his nostrils are clear, his legs look fine and I didn't see mites (though I may have missed some, I don't know). Does anyone have any idea what could be wrong? What should I do? Need help ASAP, he's the whole family's favorite!