Okay, I remember seeing this clip on PBS some years ago. This lady in England set up an obstacle course for a squirrel that always raided her bird feeder. There was only one way for the squirrel to get the food, he had to figure out the obstacles. It took a few days, but of course he did it. Squirrels are not stupid...
Good old Google. Two minutes searching and I find the video online. hahaha Unfortunately it's not that great in quality, but it's funny as hell what this squirrel will go through just to get some food.
http://www.squirrels.org/pub/course2.rm