I agree I also think we clean too much , my loft floor is deep litter , nest boxes can be left as long as dry and free from red mites , if the loft is clinically clean the super bugs evolve so its finding a happy balance somewhere in between clean boxes fer me dry droppings on floor ybs i like them to be in as much droppings as possible to build up immunity within themselves , they say your only as clean as the dirtiest loft , but the birds in the dirtiest lofts are the ones less likely to ail from the race pannier imo