The Zombies serve as a symbol of humanity’s darkest and most extreme impulses. They are referred to by many names throughout the text, including the undead; ghouls; Zack; G; and “siafu” (206), which is another name for the extremely dangerous African army ant. As nonliving humans, they serve as an inversion of organic living matter. They are humanity brought back from the dead to devour itself. They are driven solely by their most basic instincts—to hunt, kill, and eat that which is alive. They have no emotion or remorse and are “devoted to consuming all life on earth” (273), as General D’Ambrosia explains to the narrator.

Although the exact cause of the zombie outbreak is never revealed, the various political struggles around the world at its onset only serve to exacerbate the problem and render the initial responses by many countries, including the United States, to be incompetent, haphazard, and dangerous. The zombies are a product of a world in flux, where the lack of any immediate apocalyptic threat has been taken for granted. As zombies are unable to grow, evolve, or change, they demonstrate the consequences of remaining in a long period of stasis or malaise. They are a lesson to humanity to rethink its priorities, learn from its mistakes, and unite together to prepare for disaster.