Read about when fall begins, why leaves change color, and what animals do during this season. Contents: What is fall? -- Why do we have seasons? -- When does fall start? -- Why do leaves change color in fall? -- What happens to other plants in fall? -- What do animals do in fall? -- Why do animals migrate? -- What do people do in fall? -- Experiment. Interest Level: K-3 Reading Level: 2.0 Lexile Measure: 550 Guided Reading Level: H.