I’ve been buying way too many cool indie tabletop skirmish games lately for someone who doesn’t have friends or anyone to play them with.
Basic models of flocking behavior are controlled by three simple rules: 1) separation: avoid crowding neighbours (short range repulsion); 2) alignment: steer towards average heading of neighbors; 3) cohesion: steer towards average position of neighbors (long range attraction). With these three simple rules, the flock moves in an extremely realistic way.