Flocking

Flocking birds, schooling fish, swarming bees, and conforming humans aren't necessarily following a leader. In this simulation boids (virtual birds) follow three simple rules:

Alignment: Turn as your nearest neighbors turns.

Cohesion: Turn to get closer to your nearest neighbor.

Separation: Turn away if too close.

Actually, there's a fourth rule:

when a predator comes, scatter.

Here's the procedure:

to flock
find-flockmates
if any? flockmates
[ find-nearest-neighbor
ifelse distance nearest-neighbor < minimum-separation
[ separate ]
[ align cohere ]
]
end

And a screen shot: