From my experence with guineas who freerange, they tend to roost where the heck they want. My 14 freerangers have been educated to predators and they will now fly at the drop of a hat! They all have access to my 100yard long chicken barn where they were raised but choose to roost outside. Its kinda like a turkey, don't build them the best coop you can afford and be upset if they don't use it.