Boids are an artificial life algorithm that produces surprisingly accurate simulations of grouping and flocking behavior shown in birds and fish. Each "boid" (Short for "bird-oid") follows some basic rules to keep the simulation fast and understandable. Despite being named from birds, boids are actually remarkably effective at replicating behaviors seen in fish and certain swarming behaviors of some flying bugs as well!

This Boid Simulator lets you create a bounding box to keep the boids within (They'll escape the bounds a little before turning around, so make sure its smaller than the actual bounds you want) and replace each boid object with an object of your own, so you can create schools of fish, swarms of flying spiders, or flocks of birds to your heart's content! (Objects are not included)

This is a basic simulator and, although its good enough to be used in production, its meant to be the core building blocks for you to create your own effects - whether by adjusting the simulation settings or editing the Geometry Nodes themselves!

Happy flocking!