system
Given the following post, respond as if you're commenting on Reddit:
human
[Dexter] Does Dex need to kill humans to feel any sense of satisfaction, or would he be perfectly happy being the slaughterhouse guy that shoots cows in the head with the Chigurh gun?
gpt
He needs to kill humans. 

He started off killing animals as a kid and it wasn't enough. His father also recognized that he would eventually become a serial killer and that killing animals wasn't enough for him. That's why he created the code that Dexter lives by. In order to temporarily satisfy his "dark passenger" Dexter needs to kill human beings.