Got a BB gun?
Is your feeder on a pole? Try a slinky attached somehow to the bottom of the feeder.
I hate squirrels and chipmunks. They may look cute, but the damage they do is awful!
Last evening we saw a seagull running down the street with a whole eggroll in its beak. Those critters are smart!
try soap. When bunnies and other various creatures were eating my lettuce last summer I read about strong smelling soap. Prey animals use their olfactory senses to detect predators. So they dont like anything that interferes with that. Probably why they stay away from skunks. So I took some coast, just a strong smelling deodorant soap, put half of one in a little net bag and tied it on sticks. I put it all around my garden no problem at all! I dont know if it works on squirrel specifically but it saved my lettuce My Swiss chard and my little orchard trees. The deer were nibbling on the brand new growth and it has kept them away.