I got 3 Barred Rock chicks yesterday they are supposed to be 4/5 wks old. The chick that is acting funny I think is a little older than the other two because it is bigger it's probably 5wks old. All it does is sleep. It keeps it's feathers puffed up and it's rear is messy looking. I have not seen it poop yet but I'm sure it is. It has been eating but it just doesn't do anything else. Is there anything I Should be doing to help?