tired lazy chicken

[Maderia4]

One of my hens (5 months old) is acting strange. While the others are running around chasing bugs during their evening free range, Ester sometimes just stands and stares. She won't eat any of the special treats we offer and she usually roosts earlier than the others. She has done this before and then the next day seems fine. Should I have her checked. and if so who do I call.

 

[Gryphon]

I hope you get an answer from someone knowledgeable, because the 2 year old Buff Orphington hen I bought has been doing the same thing. She isn't hanging out in the nest boxes so I don't think she's broody, but she likes hanging out in the coop instead of foraging/dustbathing, isn't really interested in food, and overall looks a bit raggedy. Could these be symptoms of a moult?

 

[Maderia4]

This is my first flock of chickens I think they are red star and Rhode island reds. I know very little about chickens. Ester looks perfectly healthy she's bigger than the others and she acts lazy only occasionally.