I have spent numerous hours trying to outwit the squirrels. I thought I had them licked with my own invention. I had a 10 foot 1 inch metal pole that I greased with silicone, that I placed between a tree branch and a 6 foot fence. I then added 6, 1 foot empty paint rollers with plastic interiors on the pole. In between I hung the bird feeders.
It was a laugh a minute as the squirrels spun off the rollers, or tried to hang down by their back legs on the pole and loose their grip.
I have been battling 7 squirrels, the biggest male finally figured out the distance jump to one he could attach himself to avoiding the greased pole and paint rollers. To get even he chewed through the wire, dropping the entire feeder to the ground and took off with the top of it.
So to get even I ordered one of these: (Hang with it, you'll be cracking up.) http://www.youtube.com/watch?v=X8YZIhlWpS0&feature=related18:10:30
r.