|no seed for you!|
We have two at our house. They try, but no squirrel has ever gotten a single seed from them.
A few desperate friends of mine trap them and relocate them. When the "removed" squirrel is gone, however, several nearby ones will fight noisily over the now-vacant territory (a huge headache). The original squirrel usually finds its way back, anyway.
We use the other method too; filling feeders with safflower seed, at our house - in very vulnerably located feeders. Safflower is available at most good birding stores.