Read about what is spring, why do we have seasons, when does spring begin and what do animals and people do in spring. Contents: What is spring? -- Why do we have seasons? -- When does spring begin? -- What are the first signs of spring? -- What do animals do in the spring? -- When are animals born? -- Why do animals migrate? -- What do people do in the spring? -- Experiment. Interest Level: K-3 Reading Level: 2.1 Lexile Measure: 530 Guided Reading Level: H.