Self-organizing Criticality is much preferable to Evil Hive Mind

Zombie hording behavior is crucial to decision-making after the zombiepocalypse. Assuming that our rotting foes are dumb beasts with no mind at all may be our downfall, but all the classic texts seem to contain two fundamental assumptions:

  • Zombies have absolutely no sentience or intellect
  • Zombies gather together in hordes

Some texts also assume that zombies retain a very very rudimentary and instinctive memory of their activities as humans (crowding to shopping centres, walking along roads, etc.) but this could be a mistaken conclusion based on their hording behavior. How zombies form hordes is a key part of the zombiepocalypse puzzle: consider the ending of The Walking Dead[1] season 2, where zombies see a helicopter, follow it, and when they lose sight of it just keep walking in a straight line. This is very specific hording behavior, not necessarily matched to any existing understanding of self-organizing behavior. Understanding what happens in these kinds of situations is essential to planning anti-zombie defenses.

In most of my posts about zombie survival spots here I’ve worked on the assumption that zombies are mindless moving objects, kind of like the famous physicists’ perfect point particle. They move slowly away from their point of origin in a random direction, so if one moves away from a city one can imagine the wave of zombies emerging from the city just like a supernova, in a perfect sphere disrupted only by objects. I’ve also assumed that they follow the path of least resistance, so move along roads and open areas in preference to built up areas and forests. This means that a well-designed fence or hiding in a large complex of well-sealed buildings will tend to direct zombies away from a small group of survivors, and once the main wave of initial infecteds has spread outward, survival will become considerably easier.

However, this doesn’t seem to be how hordes function in the seminal texts. They seem to stay together and move purposively. This means, I think, that they have some kind of hording technique – some sort of self-organizing criticality, like insects. I think that their moans of bestial hunger serve the same purpose as an ant’s scent – when a zombie hears a moan, it moves towards the sound and itself moans, drawing other zombies. In The Walking Dead they also comprehend the difference between zombie and human scent, so maybe they remain close together due to some kind of scent marking process. The nature of this behavior is crucial, because if we assume that zombies horde together through a signaling mechanism and move along the path of least resistance, our tactics change:

  • Staying hidden is essential when even single zombies appear, since the sound of their bestial rage may bring others
  • Staying away from major roads is a good survival tactic
  • As roads spread out away from cities, remaining out of sight in an area far from major roads will enable survivors to escape the worst hording behavior
  • Major cities and megacities (like Tokyo, Chongqing) will have hordes of zombies potentially in the hundreds of thousands in size. If zombies have any kind of hording behavior, getting out of cities before the worst of the epidemic hits is essential. Once a significant number of zombies has been created, attempting to escape a city will be close to impossible, since being seen by even a single zombie will likely draw others very quickly
  • If zombies can horde, tactics need to be developed to enable escape from a situation where a zombie sees the group before the group sees it. This makes choice of bases and camps much harder, and makes subterfuge much more important than weapon use

I think it is reasonable to assume that zombies adopt insect-like scent-marking and hording patterns, and to find ways to fool or avoid them. The best use of this behavior is in setting up traps from which large numbers of zombies can be easily culled, or establishing distractions which enable survivor groups to flee. Understanding zombie hording behavior is essential to identifying good survival patterns. Is it an insect-like self-organizing system, some kind of voodoo, vestigial human behavior that is easily fooled, or simple particle mechanics?

fn1: which I consider to be the seminal text, much more knowledgeable than earlier efforts at Zombie science

picture taken without permission from Detrain C, Deneubourg J.Collective Decision-making and foraging patterns in ants and bees. Advances in Insect Physiology,35; 2008: 123-173.