well they do hunt with human senses,sight and sound.but even with all of their sensory abiltys or destroyed they can still hunt some how,max brooks thinks it some sort of sixth sense.no one know though
Scent....then sight. They become animalistic, instinctive....hunting with the scent humans put off. Like animals that are sensitive to human scents, not as much as animals but more than humans for sure. Then, if they happen to see someone who is alive when the scent is detected they get into kill mode. I am sure willing to bet that if a zombie walks by a human without smelling them (including exhaling our air like how mosquitoes find people) it'll continue on its way, but its too hard to do that. Its like someone smoking a cigarette. If you don't see someone smoking at all, and they stopped smoking it for a few minutes, you can still smell the smoke and realize there was someone in the area smoking a ciggy. Our breath is the same way. Bleeding too, you've got a cut they can smell the blood they so crave. Woman on their period...as inappropriate as it sounds are magnets to horde attacks. There is nothing to cover your scent for the most part, nothing to keep your scent out of their nostrils. Run, and keep moving, or fortify and I mean fucking good!!!!!!
I think it has to do with pheromones. Snakes are able to sense females that are in heat from miles away. Maybe the same applies to zombies except instead of being drive by the desire to mate, they're driven by the desire to feed.
what if zombies have the ability to sense heat like pit vipers. The virus already changes the brains chemistry who's to say it didnt make a few additions. I dont mean full heat vision, but maybe being able to tell if a body is hot or cold because zombies dont produce heat. It would explain why they dont attack each other.
even without bathing the human body is saturated with shampoos, deodorants, and perfumes. if the infected hunt by scent alone then then we pretty much paint a map to our location. i don't see a way around that. personally i believe that the infected have some sort of intelligence and the ability to evolve to become more efficient hunters. this would enplane the "grouping" around buildings with people in them. the longer you stay the more of them show up. they must have some sort of intelligence that tells them to go to the group. if they were truly without mental capacity it would be impossible for them to know when and where to gather.
Contrary to what some believe, zombies actually are totally blind. The optical nerve is all but severed after a person dies, and it is not one of the bodily functions that is brought back after the reanimation process. Instead, they hunt primarily via heightened senses of scent and sound, and will also react to changes in body temperature, at close ranges at least.
As far as masking your scent goes, roll around in mud. I'm being serious. The mud will effectively trap any scent that's coming from your body right above your skin. Granted, the mud will dry, and the scent will come out stronger from being concentrated in a general area for xx time, but it'll burn itself out much faster than if you had left it alone.
I'm for scent and sound. Think about it. They aren't suppose to be bright. Sight, isn't it. That would use brain power, but scent is subconscious and sound happens no matter what. And unless they are part snake, it is not going to be taste. What is left? Touch? Not really happening.