I put a homemade box with 3 nests with a roosting bar across the front so they can step from that into the nest. The barred rocks have taken such a fancy to it that they use it to sit and roost overnight. In the morning the nests are full of poo. They are nearing 3 months old and the RIRs are about 2 months old and showing very little interest in the nesting boxes. There are also roosts with plenty of room for all (16 chickens in all; 8 of each).
Did I put the nesting box in too soon? What might I do to correc this behavior and encourage them to use the regular roosts over night.