  This work concentrates on different aspects of the \textit{consensus
problem}, when applying it to a swarm of flocking agents. We examine the
possible influence an external agent, referred to as {\em influencing agent}
has on the flock. We prove that even a single influencing agent with a
\textit{Face Desired Orientation behaviour} that is injected into the flock is
sufficient for guaranteeing desired consensus of the flock of agents which
follow a Vicsek-inspired Model. We further show that in some cases this can be
guaranteed also in dynamic environments.
