Question

when a bee flies we hear the sound produced by its wings why can't we hear the crow's
fly

Answer 1

When a bee fly we hear the sound by its wings because the wings of a bee flap very rapidly and as it flies near us we can hear the sound produced by it. Moreover by rapid movement of wings, the pitch of sound is more whereas in case of crow, its wings size are big so they do not have to flap them rapidly to fly.