Daily. The birds roost on a platform, which I scrape every morning with a paint scraper into a catch bucket, and often treat with a little food-grade diatomaceous earth. If I notice wet or fresh droppings in the litter, I take that up too, and scrape the roosts and perches. Outside, I scrpe up any large droppings- we're roofed so we don't get wet manure much. Once a week a new blae of pine shavings goes in with some food-grade DE, and I use more of the DE around the run perimeter and in the porch and across the doorway sills.