How are birds different from other animals?

seriously? all other mammals fly and birds walk on four legs. Use your brain on this one

EDIT from horse2648: I don't know who said that up there ^, but haven't you ever heard of a flying mammal called a BAT? And birds don't have four legs. They have two. Also, not all birds fly. *coughs* What about the ostrich? The penguin? YOU use your brain on this one. Anyways...

Birds are winged animals with beaks, and give birth to young in eggs.