To join or not to join: Collective foraging strategies

We present a minimal model to address the issue of how the interaction between foragers influence their encounter rates with resources. We consider a two-dimensional lattice model to study the optimal strategy for a group of foragers (walkers) searching for targets distributed heterogeneously. A forager who has not detected any target has the choice of, either joining other foragers in the neighbourhood, who have detected targets, or continue searching independently. The optimal strategy appears to be a mixture of these choices. Remarkably, we observe that scale-free walks appear for strategies far from optimality. In general, we investigate the behaviour of the model with a parameter characterizing the propensity of the foragers to aggregate and the radius of interaction characterizing the neighbourhood of a forager.