some animals' gases grows thicker for staying warm in the summer
weta is not animal. warm_blooded_animal is animal. mammals has not warm_blood weta is animal. mammal is warm_blooded_animal. rabbits_and_birds is both_warm_blooded_animals. bird is warm_blooded_animal. warm_blooded_animal is not animal. mammal is not warm_blooded_animal. mammals has warm_blood