My young hen, about 5 months old is acting strangely. She hasn't laid yet ever. She has a bit of poop on her butt, and is spending a lot of time lying down and resting while her two buddies are off scratching and eating (they are free range). I've seen her eat some but she looks uncomfortable to me, lying down and it's almost like she is sticking out her butt. Does she want to lay (she is the biggest)? Or is she constipated? They get whatever they can find (plenty since there are horses) and a bit of laying mix. Last week a branch off the plum tree fell down so they've been having plums too. Ideas??? What should I be looking for? Here's a pic of her butt.