This model simulates how a virus spreads through a human population.
Green agents (healthy people) have a chance of becoming sick if they are within the search radius of a red agent (sick person). Each step, sick agents have a chance to recover or a chance of dying. If an agent dies it's removed from the map. If an agent recovers they are rendered grey and are immune to the disease until their immunity wears out at which point they become green, healthy agents again.