Gnat swarming behavior

The following video was made about 100 meters from the Jordan River trail
in Salt Lake City (West Jordan / Midvale), Utah. The site is a pond per-
haps one or two acres across; there are numerous birds (swallows, swifts,
red-wing and yellow-head blackbirds, etc.) around. When I first saw the
gnats, near sundown, they swarmed in a typical ellipsoidal fashion, i.e.
similar to a free-falling water balloon in slow motion. I noticed several
columns forming; in a short while, they became vertical, long and narrow.
They swayed and held shape. In gnat swarms, males and females behave
differently; in one of the vertical columns, a roughly spherical 'head' is
visible to one side, and I wonder if there might be sexual differentiation
here. What is fascinating to me is the relationship of millions of gnats
to an over-arching geometry; this parallels slime mold behavior to some
extent. I've seen lots of gnat swarms before, but nothing like this. We're
leaving the Salt Lake City area today, so I have no time to investigate
this further at the moment (we're leaving today), but I'm interested in
any further input, images, videos, you might have.

http://www.asondheim.org/gnats.mp4


Radio

'Radio' - modified recording in the Mormon Tabernacle Choir building; note
the laptop in the foreground which controls and monitors the organ, light-
ing, recording, etc., as far as I can tell.

http://www.asondheim.org/radio.mp4