I have 28 7week old bantams, 10 Cochins, 9 Brahamas and 9 New Hampshires. They are just starting to roost at night. I have a roost made from 2"X2" stock about 60" long, spaced 12" apart at about 40" off the floor. There is a droppings board 8" below the roosts. The roosts are all at the same height. The birds are roosting on many things lower than the roosts but not on the roosts. Will they work their way up or would it be better to build a ladder for access? Thanks!