You cannot win. I have been fighting "The War On Squirrels" for 20-odd (very odd) years. Unfortunately, I also have a day job, and THEY DO NOT! Their only goal in life is to outwit me (admittedly not THAT hard). In a matchup between homo sapien (with the number 1 problem-solving brain and a few hours a week to devote) vs. sciurus carolinensis (with a problem-solving brain in the top ten and 24-7 to devote) - take sciurus every time.

Long story made short - thought I had 'em licked with a Rube Goldberg 7,000 volt (DC so harmless) zapper rigged to the feeders and storage can. Worked on the squirrels for only a month - during which I got myself thrice (wetted in my pansies first time), wife twice, daughter once.