Abstract

How do animals make decisions on where to go? how do animal groups make such collective decisions? We present a spin-based model for how animal groups and single animals make navigational decisions on their direction and speed. The model describes motion that is diffusive in the disordered phase, and run-and-tumble in the ordered phase. In the presence of global inhibition, it also exhibits an intermittent phase of coexistence between stationary and moving. The model predicts a series of trajectories and a hierarchy of bifurcations in the presence of multiple identical targets. The geometry of these bifurcations is affected by the angular dependence of the interactions between the spins that represent the different targets. These predictions are compared to observations in different animal species. This model presents a new approach to decision-making in animals on the move, and as a new class of deciding-active matter.