Been thinking about Spider-Sense for a while now. It's the kind of detail that, quite frankly, ends up mattering a lot more in the comics then you'd expect. It's simple on the surface: Spider-Man can sense danger and take split-second action to avoid it, making it extremely hard for his enemies to bash, zap or otherwise cause him harm, what with the whole superhuman speed and agility deal he's got going on. The problems start once you examine what the ability does and doesn't do, and who it works against and when it doesn't.
For starters, Peter was quick to determine a means to create radio signals that he could detect with his Spider-Sense and created tracers he could affix to people and then follow them via the ability. My kudos to the man, at the time still in high school, for figuring out how to create a radio signal that a seemingly psychic ability to predict danger could detect. Was it very menacing radio waves? Was he broadcasting War of the Worlds on those Spider-Tracers?
Things get more interesting when we consider that there are three people who have displayed the ability to suppress or 'fool' spider-sense to one degree or another. The first was Norman Osborn, the Green Goblin. who created a gas that could shut it down for extended periods. The second was the alien symbiote that originally bonded to him and then to Eddie Brock, becoming Venom. This enemy doesn't trigger spider-sense at all. And finally, recently Iron Man used biometric data collected from a suit he designed for Spider-Man to create a supposed 'pheromone' means of blocking the spider-sense, which most folks dismissed as technobabble. But in fact I think it fits perfectly.
Look at it this way. Spiders have exceptionally keen tactile senses - wolf spiders can detect an intrude outside their lair, most web-spinning spiders can tell when something is on a strand of their webbing and pinpoint their location with ease. Obviously the radioactive spider bite generally enhanced Peter Parker strength, speed and general acuity to superhuman levels. Perhaps it also tuned up his senses: he can see, hear, smell, taste and has an enhanced tactile sense. But he's not cognizant of the changes, or just how far reaching they are, in part because his brain is still human and doesn't really have the wiriing a Daredevil or Wolverine has. So Peter can't consciously use these enhanced senses. But subconsciously, his advanced tactile sense combines with his other general senses to create a constant, jumped up sense of low-grade paranoia, a constant 'what's that' that translates to a buzzing in the back of his brain. His ability to detect radio signals would simply be a very high-tuned extension of that buzz all human beings have felt when entering a place with a great deal of electronic equipment humming away. And the pheromone bullshite from Iron Man suddenly makes a lot of sense: he neutralizes the spider-sense by fooling Peter with smell. Essentially, he smells like Peter so to Peter's subconscious, he is Peter. This also works for how Venom fools the sense. Venom was biologically bonded to Peter and as a result, replicated him and his abilities - in essence, Venom smells and moves so much like Peter does that to Peter's subconscious alert system, that's him back there. Finally, the Pumpkin Bombs probably worked on the same principle that causes you to tune out a horrible smell if you're around it long enough. Blanket Spider-Man in a chemical so awful that his tuned up senses won't stop screaming at him that it's bad, bad news and his brain simply stops producing the warning buzz because if it didn't, Pete would probably go insane.
Yes, i spent all morning thinking about this. My apologies.
