Most back yard feeders focus on trying to keep squirrels away from the birdseed. I had the opposite problem. Every time that I would put peanuts out for the squirrels, the birds would quickly carry them all away. So I built this bird proof squirrel feeder.
It was built from a 1x6 piece of wood (about 30 inches total), a wide mouth 2 quart jar, and two small metal hinges.