  We consider the discrete Couzin-Vicsek algorithm (CVA), which describes the
interactions of individuals among animal societies such as fish schools. In
this article, we propose a kinetic (mean-field) version of the CVA model and
provide its formal macroscopic limit. The final macroscopic model involves a
conservation equation for the density of the individuals and a non conservative
equation for the director of the mean velocity and is proved to be hyperbolic.
The derivation is based on the introduction of a non-conventional concept of a
collisional invariant of a collision operator.
