Square bins don't empty as well as something like this ... https://www.bing.com/videos/search?q=most+amazing+chicken+feeder+australia+glow+in+the+dark&&view=detail&mid=D08035B0A6BA36AD8FEDD08035B0A6BA36AD8FED&&FORM=VRDGAR
Just the part about how he tested and fine tuned the design is worth...