Everything you need to understand or teach There's A Hair in My Dirt! by Gary Larson.
When a worm family sits down to their dinner of dirt, the little worm discovers a hair in his dirt. Father Worm decides to tell him a story to restore his interest in dinner, and in being a worm at all. The story that Father Worm tells sums up more than the adventures of the fair maiden Harriet—it points out complex ecological facts and describes life from a worm's point of view.