Birds flying around in a 2D space; what more is there to say?
Boids are a popular example of how you can model real world behavior in a computer simulation. It aims to emulate how birds fly around!
To model bird/fish/bacteria flocking patterns, you must display three main characteristics: alignment, cohesion and separation. You can read more about these on the wikipedia page, but they were fairly simple to implement using Unity's built in physics/raycasting libraries. I took inspiration from Sebastian Lague's boid simulation: https://www.youtube.com/watch?v=bqtqltqcQhw, as well as Board to Bit's tutorial: https://www.youtube.com/watch?v=mjKINQigAE4.
As of right now, the birds just fly around aimlessly in a open space, which is fairly boring. I'm going to implement obstacles, maybe a procedurally generated environment and more advanced flight patterns. Might be also useful/interesting/fun to program some survival characteristics; i.e. birds too far away from the flock perish. I'll get to doing all of that after finals!