Bats can do both.
Bat
humming bird
A fly is not a mammal, reptile, or amphibian. A fly is an insect.
No flies are mammals.
A baby needs a government-issued identification, such as a passport or birth certificate, to fly on a commercial airline.
Bat is the mammal that can only fly.
Bats are a mammal that can fly.
bats... they are mammals which fly.
Bats are mammals and give birth to live young. They reproduce sexually and the mother nurses her young after they are born, usually until they can fly and find their own food.
Bats are mammals not birds, although they share some avian characteristics. They are the only mammals that can truly fly. The "flying squirrel" and gliding possum can glide for short distances, but they don't flap their wings and fly like a bat.
donno
bucks