Squirrels never succeeded in beating my Squirrel-Proof Bird Feeder Device in 2 years, except for 1 (one) occasion when the snow bank was 1 metre high.
Besides house sparrows, the bird feeder attracts blue jays and cardinals every day. There is a diagram and a couple of photos at the URL below. The big problem is that I have to refill it every 2 days!
