How do you know that they don't?

Well, I can't speak for the latest games, but I've personally read (some of) the core AI code for the toons in the first game of the series, and there was nothing in there that made a model of said code or attempted any form of what I'd even call "reasoning" throughout. No consciousness or meta-awareness.

By being simulated by the code simulating the game in which they "are", they could to some extent be said to be "aware" of certain values like their hunger level, if you really want to stretch wide the concept of "awareness". However, there seems to be no consciousness anywhere to be 'aware' (in the anthropomorphized sense) of this.

Since my priors are such that I consider it extremely unlikely that consciousness can exist without self-modeling and even more unlikely that consciousness is nonphysical, I conclude that there is a very low chance that they can be considered a "mind" with a consciousness that is aware of the pain and stimuli they receive.

The overall system is also extremely simple, in relative terms, considering the kind of AI code that's normally discussed around these parts.