I saw The Walking Dead episode where they went to the CDC and the guy explained how the dead became re-animated, etc. but I was wondering (and forgive me if it's been explained here,) how long is the re-animated life span of a walker? They need sustenance to keep on "living," right? Do they eat anything other than the non dead? I travel a lot and don't have a netfix subscription as of yet. It's hard to keep up with it all.