The influence of the physical environment on the self-organised foraging patterns of ants

Among social insects such as ants, scouts that modulate their recruiting be haviour, following simple rules based on local information, generate collec tive patterns of foraging. Here we demonstrate that features of the abiotic environment, specifically the foraging substrate, may also be influential in the emergence of group-level decisions such as the choice of one foragin g path. Experimental data and theoretical analyses show that the collective patterns can arise independently of behavioural changes of individual scou ts and can result, through self-organising processes, from the physico-chem ical properties of the environment that alter the dynamics of information t ransfer by chemical trails.