There is a kind of caterpillar in England's Lake District that has evolved to feed exclusively on the seed pods of a plant called the touch-me-not. Unfortunately for the caterpillar, the seed pods explode, without warning, to disperse their seeds. In this BBC video narrated by Bernard Cribbins you'll see a number of caterpillars having their feast interrupted when it explodes in their face. [Video]
Image: BBC