I blocked at night and left open during day for weeks. This does keep them cleaner but eventually I unblocked and what do you know poopy mats again in my boxes. I’m not sure this can correct their desire to sleep in them or poop in them. So I think I need to and now have time to place a roof over the nesting boxes because my three are open at top with just dividers so if I roof them slanted at top then how high should front be for ease of use? I may have to do both roof on boxes and blocking at night again.