  We discuss the Cucker-Smale's (C-S) particle model for flocking, deriving
precise conditions for flocking to occur when pairwise interactions are
sufficiently strong long range. We then derive a Vlasov-type kinetic model for
the C-S particle model and prove it exhibits time-asymptotic flocking behavior
for arbitrary compactly supported initial data. Finally, we introduce a
hydrodynamic description of flocking based on the C-S Vlasov-type kinetic model
and prove flocking behavior \emph{without} closure of higher moments.
