In this chapter, students gain a basic understanding of animals’ key external body parts and how different animals use them to survive or to make their lives easier. It explores specific ways animals use their external body parts to find and catch food. The chapter investigates how animals use their body parts to protect themselves from predators. It looks at the structure and function of plant parts. The chapter focuses on the engineering practice by encouraging students to design a solution to a human problem using what they have learned about plants and animals. Students learn that animals protect themselves in many different ways. They can use external body parts, behaviors, or a combination of both.