Caterpillars
          
        
        
          – and many
        
        
          other insects – chew on
        
        
          leaves. That’s their food.
        
        
          
            Birds
          
        
        
          hunt caterpillars,
        
        
          especially in spring when
        
        
          they have chicks to feed.
        
        
          
            Foxes
          
        
        
          prey on birds,
        
        
          small mammals, and
        
        
          other creatures.
        
        
          
            Autumn colours
          
        
        
          In the growing season,
        
        
          deciduous leaves
        
        
          appear green because
        
        
          of a chemical called
        
        
          chlorophyll. In autumn,
        
        
          the leaves turn yellow,
        
        
          brown, or red as the
        
        
          chlorophyll is destroyed.
        
        
          
            Making an entrance
          
        
        
          Woodpeckers use their beaks to dig
        
        
          out grubs and to make nest holes. They
        
        
          have amazingly long tongues
        
        
          to probe and seek out insects.
        
        
          A squirrel’s tail helps it to balance as it leaps from tree to tree.
        
        
          
            Deciduous forests
          
        
        
          
            Leaves
          
        
        
          act like solar
        
        
          panels to gather sunlight
        
        
          to make food.
        
        
          
            Links in a chain
          
        
        
          Food chains connect a
        
        
          species with what it eats.
        
        
          Woodpeckers have thick skulls to
        
        
          protect against the shock as they
        
        
          hammer into wood.
        
        
          
            Trees as homes
          
        
        
          Woodpeckers take two to three
        
        
          weeks to dig out a nest hole,
        
        
          into which the female lays
        
        
          several eggs. The hole is
        
        
          usually in a dead tree.
        
        
          
            Woodpecker
          
        
        
          
            Maple leaf
          
        
        
          When mature,
        
        
          a fern bud
        
        
          unrolls and
        
        
          the leaflets
        
        
          open out.
        
        
          A leaf is a tree's food
        
        
          factory. In autumn, it
        
        
          begins to shut down.