Here is a flock flying over our house. We also hear them very late at night, in the dead of dark they are completing their journey.
Here is a flock of Snow Geese. These birds are getting ready to start their journey.
Today I saw several thousand of them on the lake. One would think the water was covered with snow. This is an area where they are every single year at this time. If you stopped to listen it would be very loud, indeed.