Fish do not have ears. They have a lateral line which is pressure sensitive and therefore pics up the vibration of sound waves.
yep
the wind
I cannot.
Rapid movement of the wings.
Sometimes you can hear flapping, but mostly they are just too far away to hear it. Birds of prey tend to glide in when they attack so that their prey cannot hear them flapping and escape.Examples: owls make a soft shushing sound when they fly and mourning doves make a chirping sound that is actually their wings touching together on the down-stroke.
Owls are built for silent flight. I would base the answer off of that.
. . . so I can hear the Communists scream. Sound off . . . Sound off . . .
Bombers fly above a certain altitude (higher than a normal plane), that's why you can not hear them.
ladybugs fly by using there inside wings and swishing them up and down
They do make noise. If they fly very high, then you can't hear them.
Bald eagles have ears. They help to fly faster and to hear pray.
Because rotors are noisy and helicopters isually fly close to ground