Chickens would rather sit out in the freezing rain than go inside :(

[bantamm]

When it gets cold or snowy enough, they all go inside the coop, but if the temperature is above 20 degrees F most of them prefer to roost on top of the coop or in the tree. We had freezing rain, and only 2 out of my 7 chickens were wise enough to go inside to sleep while the rest sat outside and got wet and frozen until I put them in the coop myself. Is there anything I can do to make the coop more attractive to them than sitting out in the cold and wet?

 

[aart]

Well, what does the coop look like.....
...and how big is it, in feet by feet??

Pics and dimensions of coop will help us help you.

It maybe too small and/or stuffy in there for 7 birds.
How old are your birds?

 

[bantamm]

It's about 16-20 square feet for 7 birds, three of which are bantams. They're not quite a year old.

 

[aart]

It's about 16-20 square feet for 7 birds, three of which are bantams. They're not quite a year old.

That's an odd range of square footage to cite.....
....and may be tight for 7 birds, even if 3 are bantams.

Do you have at least 7 feet of roost length?
What about ventilation?

Will you post pics of coop, inside and out?