Yes, hunger. If worms overpopulate they run out of food and die off until it’s sustainable. And if there are too many birds they will starve bc they would eat most of the flies. Then flies will repopulate and so will birds a little and things will eventually get balanced out
Bruh just add data to pixels. Like with heat. If a pixel eats it gets more numbers on its hunger and the that number goes down and if it goes to zero the pixel dies