I did Like to start with this quote :
Like there is a soul behind this body,
there is an animal behind beneath this flesh.
Humans who have a face, an identity to the Soul within, they way the human mind works is greatly inflused by the animalistic instincts. the way it mates, the way it acts, the way it survives, the way it fights back, humans are fundementally animals, but having the advantage of the mind, they intpret the happenings or the urges in a different way, since they are control freaks, they create rules, regulate the happenings.
This is a Curse to the humans for all the ill effects, and boon to its achievements.