Measuring Stigmergy: The Case of Foraging Ants

Software today is no longer monolithic, but typically part of a system consisting of many components. As engineers are no longer in control of the entire system, novel methods are sought to design complex software systems that are built from the bottom up and are robust in a dynamically changing environment. The coordination method called stigmergy that is inspired by the collective behavior of social insects is one of the candidates to help solving this problem. In this paper we make a first step in formally understanding the essence of stigmergetic behavior by studying the famous ant foraging model of Deneubourg et al. We explore the relationship between the initial (dis)order in the environment and the performance of the ant foraging behavior. We further study how this configuration of the task to solve governs the behavior of the ant colony, with special focus on the level of coordination that is achieved.