The model has a 51651 lattice structure, where each cell of the lattice corresponds to a group's territory. We assumed disease transmission can occur between each group and its eight neighbours (Fig. 1) . We use N i to denote the list of indices of the eight neighbours of group i. Initially, a single habitat hotspot is placed at the center of the lattice. All groups are assumed to include ten individuals. At each daily time step, each group either visits the hotspot or stays in its territory. The probability P visit i ð Þ of a visit by group i is a decreasing function of the Euclidean distance, d i , between the group's territory and the hotspot. We assume that all groups gain the same benefit from visiting the hotspot and that the travel cost is proportional to d i , leading to: