Chipmunks are cute, but tough. A few years ago, I saw one dive repeatedly into an underground bumblebee nest to feast on the colony's larvae. The bees, no surprise, went on the counterattack. In response, the chipmunk would shoot out of the nest like a rocket, shake himself off, and dive right back in.
Mind you, even the toughest rodent knows that a painless meal is preferable to a painful one. Which explains why the chipmunk in this picture has decided that our bird feeder, stuffed with sunflower seeds, is his personal larder:
Click to enlarge.
Don't think, though, that chipmunks restrict their diet to seeds and the occasional insect. They may also eat fungi, eggs, frogs, worms, and, according to some accounts, the occasional small bird or mammal. They will even eat small snakes.
As for big snakes, they eat chipmunks. That's nature for you.