Fig 7. Simulation of a single colony in 100 m².

Simulation was run until 25% of the area was covered by discs, about 145 years. Densities this high probably rarely occur in nature, but illustrate the principles of the simulation. Blue indicates a shallow source of soil, while red indicates admixture of deepest layers. Colonies move a mean of 4 m per year in random directions (see text for details).