The difference from birds is that bats have no feathers but have evolved their forelimbs so they can fly using a thin membrane that stretches between their four long, thin fingers.
和鳥類不同的是，它們的翅膀沒有羽毛，而是由前肢演化而成，四根細而長的手指間，長著一片可伸縮的薄膜，就是它們的飛行利器。