A lethargic chicken can mean many many things. Last time I had a lethargic hen it ended up being liver failure. She could have a parasite, disease or it could be the temperature. Examin her very carefully, looks for wounds and parasites or symptoms of some sort. If you can help her with eating and drinking do that and separate her from the rest of your flock.We have a Dark Brahma hen that is very sleepy and not moving much. she hasn't eaten or drank at all this morning. She is not broody, and she's not standing in an egg bound position, So any Idea what she has and how to treat it?