Thick fur can be used for keeping warm, and becuse of that, the fat layer was needed to keep warm, now that the fur coat was removed. Given these facts, what do animals without thick fur need to stay warm among the following options:
- colder weather
 - less fat
 - In the winter
 - hard outer covering
 - layers of fat
 - thinner fur
 - nutrients
 - hydrogen and oxygen


 

     layers of fat    