One problem with the module's simulation is the formation of long dendritic structures, which do not occur so frequently in biofilms (see Figure 10.5.2, t = 125). We have not considered the loss of pieces from the biofilm due to erosion, abrasion, grazing, or sloughing (Picioreanu et al. 1996). Adjust the biofilm simulation so that it shows the erosion of surface bacteria. Similar to Project 1, release an inert particle one at a time from a random location east of the biofilm and have the particle go on a random walk. If the particle touches a bacterium (i.e., a neighbor to its north, east, south, or west), re-move the bacterium, making its cell empty. Have biofilm execute one step of this random walk (after consumption) at each time step. Notice that erosion only occurs on the surface of the biofilm. Discuss the impact of allowing ero-sion on the structure. Which bacteria are more likely to erode?