Hello, we have 5 chickens that are about 16 weeks old. Last night we noticed one chicken didn't want to go in the coop at dark. Thought she needed more time, came back out at 10:30 and she was asleep under the coop by herself so I moved her inside. This morning she was last out of coop and run and then quickly went off on her own and is standing in a puddle of water for quite some time. I also saw her regurgitate clear thick liquid. What could be wrong with her?