I never tire of watching the great winter flocks of birds like starlings, moving with eerie grace like some superorganism, supposedly by obeying very simple rules. (Photo, sent anonymously a year or two ago, by Manuel Presti; thanks, PD!)
This is most obvious when birds are under attack.Bill Kessler sent this amazing YouTube filmed in the Netherlands of a flock being harassed by a sparrowhawk, which eventually splits the “organism” in half, making it fission like an amoeba.
Richard Barnes’ Animal Logic, a wonderful book of photographs which also features things like deconstructed museum dioramas and skulls (deconstructed in this case a Good Thing) has an excellent selection of photos of starlings flocking in Rome.
(Animal Logic also has an essay by the always quotable Jonathan Rosen which may show up in Commonplace Book soon).