I have watched most of the first season of The Walking Dead and I do not understand one thing; why do the walkers need to eat in the first place? Does their digestive system work? If so, why would it, they are basically dead as I understand it. There would be no biological reason for them to eat and no way for them to process what they have eaten afterwards.

It's a great show but I can't get past this small point. I don't see them going on and drinking water either...

  • Already answered: scifi.stackexchange.com/questions/106421/…
    – wcullen
    Commented Nov 9, 2017 at 3:39
  • 2
    @wcullen - That’s a duplicate of a closed question on another site. :)
    – Obie 2.0
    Commented Nov 9, 2017 at 9:13
  • 2
    Think it's more of a residual primal urge than a biological need. Commented Nov 9, 2017 at 16:42
  • Might as well ask How can they even walk if their muscles cannot metabolize? Commented Mar 4, 2018 at 19:58

2 Answers 2


The walkers are dead, they do not need to eat nor do their intestines work. If you are going to accept that living-dead zombies are possible you have to suspend your disbelief.

That said, there are some analogues to the real world with parasites. The closest one that I can think of is this one:

Instead, the microorganism is somehow able to recognize the brains of different ant species, and releases its mind-controlling chemical cocktail only when in its preferred host, new research shows.

"Behavioral manipulation is such a complex [characteristic] that it only occurs when there's a very close coevolution between pathogen and host," said Charissa de Bekker, a molecular biologist at Pennsylvania State University and lead author of the new study, published in August in the journal BMC Evolutionary Biology.

In the first season, Rick and the gang travel to the CDC and it's discovered that everyone has this virus. So, theoretically, the virus could be making the zombies bite/attack the living in an effort to spread itself. Of course this wouldn't be an intelligent process, but rather through natural selection it's what 'worked'.

  • 1
    In a typical zombie movie/TV show, this might be accurate. However, it's not likely that the "fungus" would seek to spread itself if everyone is already infected with it; that type of genetic mutation would only be necessary to ensure its survival. Commented Nov 9, 2017 at 14:19
  • 1
    Why would the zombies need to spread the virus if everybody has it? If anything, destroying people by eating them creates less zombies and less opportunities to spread viruses. Commented Nov 9, 2017 at 14:21
  • @JohnnyBones (and Broneironaut): (1) What if the "inherent" disease (that we all carry) is dormant, but an advanced version of the disease (achieved by having the disease fester in a corpse) can activate the dormant disease (a bit then transfers the advanced disease, which kickstarts the dormant disease). More complicated, but not impossible. (2) The virus' biting behavior may also be an evolutionary remnant; similar to why humans still have a coccyx even though we have no tail anymore. The virus doesn't know that everyone is infected, so it just does what its DNA tells it to do.
    – Flater
    Commented Nov 9, 2017 at 15:12
  • @JohnnyBones: (3) Alternatively, the dormant virus only takes control of the host when they are dead. The bites could simply be there to speed up the mortality rate (by killing the human, but not actually affecting the dormant virus), thus allowing the virus to "blossom" in bigger numbers.
    – Flater
    Commented Nov 9, 2017 at 15:13
  • @Flater - Too much conjecture. There is a close vote for questions that specifically states the question is opinion based. I don't think this question is opinion-based, but there's no proof in the series that anything you said exists, which makes those suggestions opinion-based. Commented Nov 9, 2017 at 15:40

I'm going to combine a few pieces of an article I found and present this (paraphrased) explanation. Romero, as you probably guessed, is George Romero, creator of the landmark Night of the Living Dead (1968)

As for investing such time and effort in such zombie minutia, Romero, who we're treating as the de facto authority on all things zombie, because he kind of is, has criticised people in the past for taking his work too seriously including Max Brooks, who you may recognise as the author of the best selling Zombie Survival Guide. Romero has always maintained that the focus of his movies isn't the zombies - it's us, or rather our reaction to them and that the zombies and how they function isn't important. Romero went on to explain that although his zombies do indeed eat human flesh, he's never given much thought as to why they do this and even expressed amusement at the idea of a film exploring the idea of, as he put it, "Do they [zombies] shit?"

Robert Kirkman, the creator of the immensely popular Walking Dead series has stated that he will never reveal how the original zombie outbreak started or how the zombies infect through biting because it's "unimportant" to the story.

This article is a bit outdated, as we learn in the series that zombies don't actually infect through biting, but most everyone who followed Romero's work usually follows the basic principals by which Romero's zombies function.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .