The milling pattern in animal groups and its dependence on the density and on the number of particles

Abstract

Moving animal groups often exhibit aggregation behavior. In many species, the collective behavior invariably depends on local interactions among individuals. In such groups, the mechanism of group formation require that interaction rules be followed by all members, and as consequence, animal aggregates such as schools of fish, flocks of birds, and swarms of locusts exhibit a variety of dynamical behavior patterns. In this paper we investigated only the milling pattern. Of particular interest to us is to analyze its dependence on the density and on the number of particles. We found that the milling formation depends of these two physical quantities.