Let's start with the basics. Energy vampires are usually lower vibrating individuals who feed off the life force energy of higher vibrating people. This is sometimes being done on a conscious level but often times it's unconscious. On a spiritual level, they are likely souls contracted to come here and force you (the empath) into learning to love yourself. After all, that is what most empaths are here to learn; love of self. I like to call them the teachers in the negative space.