My wife made this awesome treadle feeder. We later learned that the feed pan should be much deeper to reduce the birds from running their beaks through the feed, spilling feed all over the ground. I got tired of this, so I made this insert to reduce their ability to do this. They have to get feed out of a small hole...they can't bill the feed. It has worked like a charm. I used a piece of 1/4" plywood, drilling I think 2-3" holes. It fits just snug and is easy for me to remove.