My Squirrel Feeder
A few years back I found a "squirrel-proof" feeder at the Green Center (our local recycle center). It was in great condition and for a while it worked as a barrier to gray squirrels. The smaller red squirrels could squeeze between the wires. However over time the gray squirrels worked around the lid of the tube. They chewed the plastic so they could stick their head inside. Eventually I expect to find one these guys completely inside the tube.