Feathers help birds fly and provide insulation, and birds have bodies covered with feathers. Given these facts, what is one reason birds have covered bodies among the following options:
- To help them burrow
 - They have thick fur
 - layers of fat
 - To help them fly
 - To keep their body heat.
 - To attract predators
 - with their fur
 - To make them heavier


 

    To help them fly     