Collective motion as a distinct behavioral state of the individual

Collective motion is an important biological phenomenon, ubiquitous among different organisms. Locusts are a quintessential example of collective motion: while displaying a minimal level of cooperation between individuals, swarms of millions are highly robust and persistent. Using desert locusts in a series of carefully controlled laboratory experiments, we show that locust coordinated marching induces a distinct behavioral mode in the individual that we term a ״collective-motion-state״. Importantly, this state is not induced by aggregation or crowding per-se, but only following collective motion. It is manifested in specific walking behavior kinematics and has a lasting effect. Simulations confirm that the collective-motion-state provides an individual-based mechanism, which increases the robustness and stability of swarms in the presence of fluctuations. Overall, our findings suggest that collective-motion is more than an emergent property of the group, but a specific behavioral mode that is rooted in endogenous biological mechanisms of the individual.