Emergent Transition from Radial Foraging to Tree-like Raiding Patterns Induced by Complete Following for Pheromone

Open Access

Abstract:  Among ants that show complex and diverse collective actions, army ants are known to raid prey in groups. It has been confirmed that the characteristic pattern in a swarm raid of army ants changes from radial to tree-like with time. There are some simulation studies focusing only on the emergence of tree-like patterns. However, the models adopted in their simulations cannot represent the transition of patterns from radial to tree-like observed in the real world. In this study, we propose an army ant model with a modification of the model adopted by Solé et al. and clarify the conditions of the emergence of the transition. From the experimental simulation results of our model, we deduce that the simple modification of the Solé model can move individuals in eight directions, but it is not enough to express multidirectional to unidirectional convergence. Additionally, our simulation experiments showed that for the pattern transition from radial to tree-like, it is necessary for the individuals to keep moving forward until they get food, and for the returning individual to completely follow the pheromone.

Keywords: army ant model, radial foraging pattern, tree-like raiding pattern, swarm raid, complete following for pheromone.