a basic “eat/mate/die” simulation in Processing. Creatures wander around the screen looking for food. When they are no longer hungry they begin a mating dance by slowly circling the center of the screen. If they are able to crash into each with sufficient velocity they will mate and reproduce. Eventually the creatures die of old age, or starvation, and become food for the surviving creatures to eat.
blog post at: http://lav.io/2013/10/simulation-eatmatedie/