Soldier Crab Swarming and Dual Neighborhood System modelYukio-Pegio Gunji (Kobe University)Soldier crabs in Japan make a big swarming composed of from hundredsto several thousands individuals. ;>From the observation of soldiercrab behavior we constructed a model for swarming, featuring two kinds of neighborhood. Our model can mimic the wondering behavior of swarms,mass effect to crossing the water, and oscillating behavior in aclosed container (crab clock). It also explains the scale-freecorrelation, which recently found in a bird flock. Because our model contains inherent noise that can actively contribute to form acoherent swarm, it can make it possible that coherent swarm masscoexists with critical behavior associated with the power low.Compared with boids, we show that swarms in our model are robust against external perturbation. Less