Unusual behavior - sitting around and not roosting

[colospgs]

About two months ago, one of by BOs started just sitting around most of the day instead of walking around. It's been a hot summer so I didn't think much of it. She's still doing it even though its cooled considerably. Now, for the third night in a row she decided to sleep in the nest box instead of the roost. Even when free ranging, which is the most exciting time of the day for the flock, she'll still spend some time sitting on the grass. She seems to walk fine (no limping) but sometimes I think "Did I see a limp there?" But if I did it was once, then fine. Her egg laying seems okay.
Any ideas on if anything is going on here, or do they sometimes change behavior inexplicably?

 

[rosemarythyme]

How old is she? How high up are your roosts? Is she a heavier bird than your others?

 

[colospgs]

About 2 years old. TSC coop so roosts are about 9" above poop tray. About same weight as the others, although she may have, not sure, lost some weight during these last two months

 

[rosemarythyme]

Hmm unusual for leg or foot injury then, since the roosts aren't high and she's still fairly young. I assume you've checked for bumblefoot or any sort of swelling in the feet?

 

[colospgs]

Thank you for your input rosemarythyme. Things have gotten worse (I think), so I am going to post a new thread in the injuries/cures forum.