I have 12 pullets and 1/2 are pilling in the nest boxes at night. I can't block them off because my 8 older girls use the nest boxes in the day time. My roost bars are all at the same level and make an "L" around two sides of our coop. The coop is 8' x 10', so there is 80' of roosting bars. We should have plenty of room for 20 chickens. I have two hens that are 3 yrs old and they have always roasted on one end of the "L" and the six other hens are 1 1/2 yrs old and roast on the opposite end of the "L". So there is plenty of room in the middle for the pullets.. In fact that's were 1/2 of them go. But every night I have to move the others up onto the bar and then they stay there all night. Will they eventually figure it out on their own? I've never had this problem before. Here's some pictures to show our setup before the girls ever moved in.