I guess it is a nesting thing according to all of your replies!
The coop isn"t cold inside.
I am in california south of San Francisco, so it has been in the 60's.
It was funny to watch, and the other hen was watching her like she was trying to figure out what was happening!
I know I read somewhere about this behavior but can"t find it, so I'm asking.
Today my RIR was acting wo weird!
I now she was gong to lay an egg cuz she was being super loud, and kept going in and out of the coop.
At one point she went in, made a little nest, and laid down.
But no egg.
Then...