This movie is base on Mike Carey's novel which uses another metaphor trying to explain human condition. When you see monsters, ghosts, all sorts of weird things in movies, you should learn to look at them in different way. Because they usually point to a specific human condition that only exists in human psyche.
This movie is about an infection that turns humans into human-eating-people. When they are infected they become unconscious and all they desire is to eat human.
When they smell a human, they can't help themselves and they eat them alive.
When you watch those moments of attack , do you find any similarities in your life?
Like when you attack all the food you can find because you feel too hungry?
Or when you lose control and attack people around you with your words or fist?
In all those moments we are triggered by something and we fall into a trap because we are not conscious enough
like those hungries in the movie, they have a trigger but since they lost all the consciousness they have no way of controlling themselves
but then there a little girl, who is like them but she is conscious
She is aware of her impulse but she does not deny it. She feels when it is triggered, and she tries to contain it in a less harmful way. She does not want to hurt people she loves. And she finds different ways at the end.
When we ignore our impulses, we can never know when it is triggered
And when we don't know when it is triggered, we will keep hurting others and ourselves
and at the end we end up becoming like hungries who loses all at the end.