A MODEL FOR THE EMERGENCE OF PILLARS, WALLS AND ROYAL CHAMBERS IN TERMITE NESTS

A simple model of the emergence of pillars in termite nests by Deneubo urg is modified to include several additional features that break the homogeneity of the original model: (i) a convection air stream that dr ives molecules of pheromone along a given direction; (ii) a net flux o f individuals in a specific direction; (iii) a well-defined self-maint ained pheromone trail; and (iv) a pheromonal template representing the effect of the presence of a queen that continuously emits pheromone. It is shown that, under certain conditions, pillars are transformed in to walls or galleries or chambers, and that this transformation may no t be driven by any change in the termites' behaviour. Because the same type of response at the individual level can generate different patte rns under different conditions, and because previous construction modi fies current building conditions, we hypothesize that nest complexity can result from the unfolding of a morphogenetic process that progress ively generates a diversity of history-dependent structures.