Because they have the same characteristics such as warm-blooded, egg-laying, feathered vertebrates of the class Aves, having forelimbs modified to form wings.
What distinguishes Birds from other animals is the presence of feathers.
no they cant fly because it weighs down their wings
some birds are to big for their wings to make them fly
Roosters, Chickens, Penguins, Ostrich.
Two, all birds have two wings.
To say that birds use wings and feathers to fly, so all birds can fly, would be false. Not all birds can fly. An ostrich is an example of a bird that cannot fly.
Wings
because they have wings
wings
Ones with Wings
wings
Insects that have wings can fly. They fly with their wings like birds.
birds can fly because they have such small, light bones in their wings.