At 22 seconds you will see an aero fly into a green Orb and disappear. Here will learn that they communicate while in flight; because you witness the green Orb blinks in preparation for the incoming aero.
See the red triangle that the aeros have placed in the cloud. Notice how the cloud housing the triangle is much darker than the surrounding clouds.
See more at www.youtube.com/aerostockians
This is what the quantity of aeros in the skies looked like last night (Mon24Nov08) when the girls and I attempted to capture the airborne Night Circles on video.