I have a 30 pound hanging feeder and it usually has the little pellets of feed in it. They have never spilled any out. I bought a different type from another feed store that was little crumbs and in 3 days my two hens knocked 20 of the 30 pounds out allover the coop floor all by themselves. The gap between the container and bottom is set to its narrowest. The food does not spill out on its own, they are actually flicking it out with their beaks. How can I stop them?