poop trays are like poop boards that many use. Sprinkle the board/tray with sand or PDZ and scoop with kitty litter pooper scooper (or similar) to remove poop. Allows you to go longer before replacing the bedding in the coop. However, if you are getting a coop that is as large as the picture seems to indicate, and it is walk in, you may likely find that you actually prefer to scoop poop inside your coop, rather than standing in the wind/rain/snow/whatever while scooping poop. Besides, how will the poop tray be supported while you slide out and scoop? With smaller coops sold for fewer birds, its not a problem as the tray (or trays) is/are smaller, but beyond 2x2' or similar trays, it would get unwieldy pretty quick.