Defines annelids, such as blood-sucking leeches and earthworms, and describes their physical characteristics, life cycles, habitats, senses, food, and means of self-defense.

What are annelids? -- Annelid bodies -- The life cycles of annelids -- Where annelids live -- How annelids sense the world -- What annelids eat -- How annelids defend themselves -- Up close: blood-sucking leeches -- Up close: earthworms that live on land -- Where can you see annelids?.