This morning I went out to feed the chickens like usual and i noticed one of my Rhode Island Red hens (who usually is constantly up foraging) was laying down with her eyes closed. I was worried so i went over to her and checked her eyes and nostrils and and everything looked fine. Also listened to her breath. She wasn't wheezing or anything. So I put her back down and she acts fine just sleepy. Then I saw her yawn a couple times. Is it possible that shes fine but just tired? Or is that a sign of sickness? Other than seeming tired she was perfectly normal. Also she has been laying but has not laid the past two days if that helps.