Yea! Two people got the answer right. A rat proof feeder also stops wild birds. I have repeated the details ad nauseum today, spring loaded door, heavy counterweight system, and a narrow and distant treadle are all required.
Google Fifth Crow Farms and chicken feeder or
here is the link to the story. They got a grant to buy twenty of my feeders years ago and within days their wild bird problem was gone. Since then they have bought about the same amount and other than a few dozen springs they have been working ever since. Their salad greens crops were being ruined and they were feeding an extra twenty pounds of feed a day. After the feeders were installed on pallets, outside in a free range pasture, the birds left for good.
All this proves what Howard E. has said over and over again in his posts, sanitation, exclusion, elimination are the steps to take to deal with vermin. Start with the first step and the other two are not needed. It would be impossible to rat proof or wild bird proof acres of land. There would be no end to trapping and poison purchase to protect acres of land. But a simple rat proof chicken feeder solved the problems and has been working flawlessly for going on six years.
One thing they did right was put the feeders up out of the poo to prevent corrosion, chicken poo is very corrosive, the ammonia in it. One thing they could have done better was allow the treadle to bottom out on something to make training easier, but they got it close enough that the hens can hold the treadle with one foot and stand on the other foot so it has worked for them.