In autumn, leaves drop to the ground. Many trees have nuts or fruits. Animals may begin to store food. Some birds collect nuts and acorns to store. Other birds fly to a warmer place for winter. They won't return until spring. Days become shorter. Cold weather is coming. The fur of many animals gets thicker because they need a thick coat to protect themselves. People also wear warmer clothing and prepare for winter. In some areas there may be rain or even snow, but in many southern areas it is still warm. Autumn is also the time when farmers harvest their crops. People look forward to autumn for many reasons. The most important one is that autumn is the harvest season.