flocking

Flocking is a collective motion phenomenon in which individuals move together in a coordinated way, usually without centralized control. It is observed in birds, fish, and some insects and mammals, forming large, dynamic groups that exhibit coherent movement.

The behavior arises from simple local interaction rules. Individuals typically follow alignment (matching the direction of nearby neighbors), cohesion (steering toward the average position of neighbors), and separation (avoiding crowding or collisions). Each member acts based on information within a limited perception radius, and the aggregation of these local decisions produces global synchronization.

The concept has been formalized in computational models such as the Boids simulation by Craig Reynolds, which implements three steering behaviors corresponding to the local rules. Variants explore factors like noise, obstacle avoidance, and finite perception, helping researchers study how complex group patterns emerge from simple instincts.

Natural patterns include murmurations of starlings, which create rapidly changing, fluid shapes, and V-formations observed in some migratory birds that may reduce energy expenditure. Similar patterns appear in fish schools and insect swarms. The specific structures depend on factors such as density, speed, environment, and predator presence.

Flocking is used in biology and physics to study emergent collective behavior and in applied fields such as computer animation, robotics, and autonomous systems. Researchers measure metrics like polarization and angular momentum to quantify the degree of order within flocks.