video credit: Mark Rober*
not as much fun, but a simpler solution: place the feeder on a support far enough from anywhere a squirrel can jump from to reach it in one leap, and surround the support up to the height of the base of the feeder with single sheets of glass – each too wide for a squirrel to reach across – held in place only at the top and bottom
also: side-by-side pieces of lumber could hold the sheets of glass in place and allow easy removal for cleaning
also: side-by-side pieces of lumber could hold the sheets of glass in place and allow easy removal for cleaning
on second thought, just enjoy the video
*a link – see a note on notes and links