Possible answers:
1). To help them burrow;
2). They have thick fur;
3). layers of fat;
4). To help them fly;
5). To keep their body heat.;
6). To attract predators;
7). with their fur;
8). To make them heavier;

Fact 1: Feathers help birds fly and provide insulation. Fact 2: Birds have bodies covered with feathers. Given the two facts above, what is one reason birds have covered bodies?
Answer:
4).