Are they birds or humans?
They know how to build.
Their city flys, so they know engineering.
Could their city be called a ufo?
Does their appearance explain alien sightings?
Not floating out of a ship but gliding out of the city.
Redefines the bird man from Alcatraz.
Was he one of them?
Will we ever see their homes?
Do hurricanes or tornadoes effect their city?
Could there be an over population of birds?
Might they build another city?
If we can get there are humans welcome?