For vampires, blood drinking can be compared to humans consuming food and drinks; they need to drink the blood of the living to survive. In addition to blood, vampires commonly have been thought to consume other essences of the human body, including thoughts, saliva, and fluids exchanged during sexual activity.

That drinking a vampire's blood could turn a person into a vampire was grounded in stories at least several hundred years old, but this was something different–the most common trait was that if a human consumed a vampire's blood, it could transfer power, enhance senses, or heal someone.

However, it was implied by both of these highly disciplined vampires that it takes time and practice to learn to live exclusively on vampire blood; in most other instances, vampires will only feed on other vampires as a last resort similarly to their stance on animal blood, otherwise it either never crosses their minds ...

Blood is essential for vampires due to how they kill and receive life through blood. When vampires bite, they receive strength and energy which gives them life. While doing this, they are killing souls by drinking their blood in order to regain their own life.