hese collectively are referred to as the Infected (noun) in the game. Individuals who have just been infected are classified as Runners. They still cling to a shred of their humanity, however small, and try to resist the fungus’ behavioral control. However, if they are startled or as the infection progresses, they will snap and attempt to attack anyone nearby who is healthy. Stalkers are fully controlled by O. unilateralis and start to show fungal growth on the face. This fungus strain attacks the eyes first, so they have poor vision and begin to exhibit primitive signs of echolocation. In Clickers, the face has been fully engulfed by fungal growth and rendered the host completely blind. These Infecteds use clicking and screeching to crudely survey their surroundings within a small radius. The growth on the head and face forms a roughly dish shaped plate that helps to direct the clicks. Bloaters are the final stage and can take 10-15 years to develop. The entire body of this Infected is now covered in fungus, some of it showing bioluminescence, and is therefore very physically hardy. Bloaters are also able to throw sacs of toxic powder both as a defense and an attack mechanism. Once the host finally dies, whatever tissue is left of the former person crumbles and is used by the parasite to complete its growth and release spores.
Now to analyze the behavior of the Infected. All stages appear to seek out specific locations and stay there, unless stimulated to pass on the infection when a healthy individual is sensed nearby. This reflects the behavior of O. unilateralis controlled ants that travel until they find the optimal conditions for the fungus’s reproduction and then fix themselves to that spot. However, infected ants will leave the colony and do not show any aggressive behavior whatsoever toward other ants. Why would the Infected exhibit such an aggressive drive to bite or kill? We actually have a disease in existence that does just this. It’s called rabies virus. If rabies can infiltrate the brains of mammals and stimulate this type of behavior, it would not be a stretch to think that a mutant fungus could affect humans this way. Rabies in humans doesn’t present the same way that it does in other mammals; it resembles a bad flu, followed by agitated behavior and cognitive deficits, sometimes with hallucinations, delirium, and insomnia. Perhaps our mutant O. unilateralis would be able to incite the aggressive behavior seen in the games by affecting the brain in a similar way to rabies in non-human mammals. This could explain the Infecteds’ responses to healthy humans.
Runners display behavioral tendencies that would be expected. Since the fungus has only just started infiltrating the brain, it is not surprising that the victim would be scared and confused by what is happening. It makes sense that a person in this state would be very volatile and dangerous to approach. Stalkers tend to hide out of sight and only engage when someone lets their guard down. This is presumably because their vision is extremely poor and they must wait until the opportune moment in order to successfully attack. Clickers are harder to explain realistically. It would be highly unlikely that an Infected would suddenly develop the ability to navigate using clicks. This is a skill that must utilize learning and memory, parts of the brain no longer accessible to the victim. Very few humans are able to echolocate and those who are have refined their technique over years. Real world O. unilateralis is not able to direct ants to do things they are not already capable of; it simply takes advantage of abilities the insect already possesses. The sense that would be most beneficial to a Clicker is touch. Of course, sound is still an effective way of interacting with surroundings, but it would not be used for spatial navigation as in The Last of Us. This can be extrapolated to the Bloaters in the game as well, because they also use echolocation. All of these Infected will attack to kill. This is presumably because the fungus cannot kill immediately on it