I have a flock of free ranging production red hens, they're about 13-14 weeks old. It's been really warm today so I refreshed their waterer just a few minutes ago(they have several waterers all around the lot). and they all came running to me as usual, but one of them was squaking more than usual, and she's walking around as though something's bothering her rear end, she's kind of crouching as she walks, keeping her butt towards the ground. when I first noticed it was as she came out from under our back deck, I don't think there's anything under there that would hurt her? I tried to look her over, didn't see any obvious injuries, blood, etc. but she is particularly skiddish so I couldn't really get a close-up look at her bum area. any ideas? I really hope she's ok!