The nature of science (NOS) describes what science is and how knowledge in science is developed (NSTA 2013). To develop elementary students' understandings of how scientists explore the world, the authors--an education professor and a third-grade teacher--endeavored to integrate NOS into a third-grade life science unit. Throughout the lesson, they emphasized the students acting as scientists; however, their main focus was on how and why scientists use models. This aligns with the "Next Generation Science Standard" science and engineering practice Developing and Using Models, as the "organisms" served as models of live animals. With scaffolding, the students were able to collect and analyze data to answer a question about the natural world. Students recognized the components of NOS that correlated to the lesson, especially why models are needed to represent concepts or objects.