This model simulates how a virus spreads and perpetuates in a human population.
Green agents (healthy people) have a chance of becoming sick if they share the same space with a red agent (sick person). Agents that are grey are immune to the disease until their immunity wears out and they become green agents again.
Each step in this simulation represents a week.
Agents randomly move around until they die from sickness or from old age. The life span of each agent is 50 years (or 2600 weeks). Each step, red agents have a chance to recover. If a red agents remains sick for the entirety of the sickness duration then they die.