All my chickens sleep in the nesting boxes. How can I get them to roost?

[BoiseChik]

We have 6 chickens that are 14 weeks old, and another group of 6 that are 8 weeks old. Our coop is divided for now, to keep the older group from picking on the younger group. Both sides of the coop has roosting posts and both sides have nesting boxes lined with sawdust. All the chickens seem to prefer to sleep in the nesting boxes at night. None of them are laying yet, but when they do start, I'm thinking this will be a problem.
Is this a problem that needs correcting or should I not worry about it?

 

[chfite]

They may not be inclined to roost at this age, but close off the nesting boxes until they get closer to the age of laying. The roosting bars need to be higher than the nest boxes.

Chris

 

[BoiseChik]

Our coop is basically two boxes that are 3'x3'x3' square, and connected by a pass through. The roosting posts and the nesting boxes are all about 12" off of the ground, and I checked their relative height and it is within an inch or two. What would your recommendation be? Should I move the roosting posts up further? And if so, how much further? Or maybe I should ask, how far from the ceiling should they be? Thanks for your help!