Feathers help birds fly and provide insulation, and class Aves is for the birds, literally. Given these facts, feathers help what kind of animals fly and provide insulation among the following options:
- preventing heat transfer
 - dragons
 - passenger pigeons
 - butterflies
 - animals in the class Aves
 - airplanes
 - it protects them
 - retaining heat


 

     animals in the class Aves    