[Wikipedia] Boids (which refers to a bird-like object) is an example of emergent behavior; that is, the complexity of Boids arises from the interaction of individual agents (the boids, in this case) adhering to a set of simple rules. The rules applied in the simplest Boids world are as follows:

• Separation: steer to avoid crowding local flockmates
• Alignment: steer towards the average heading of local flockmates
• Cohesion: steer to move towards the average position (center of mass) of local flockmates

Only separation	Only alignment	Only cohesion

• All the behaviors are abstracted behind FlockBehavior interface.
• All the applied behaviors are determined from FlockBehaviorProcessor class, you may add / modify / remove any behavior easily from here as desired.

Thanks to Daniel Shiffman for his awesome video about boids / flocking simulation.