Animals must act according to their preprogrammed nature. Its self is completely immersed in its nature. An angel has a self, like a person; but it also has a nature. An angel has no free will. It must do what it is programmed to do. Man, on the other hand, has a self and has free will. We are not guided solely by our nature and instincts. Each angel represents something different or is the messenger of a different attribute. That will guide his actions.