In Deet part-1 I think we safely established that DEET isn’t a four-letter-word. uh. yeah. DEET is also clearly more widely accepted than some of the ‘natural product’ propaganda advertisements would lead you to believe (“CONTAINS NO DEET!” “CHEMICALS ARE THE DEVIL” “HIDE YOUR CHILDREN AND FRAIL UNCLES” “NO MSG!”)*.
I had to be a bit choosy with my wording in the comic though because the mechanism that allows DEET to be so successful has been a topic of debate since its introduction over 5 decades ago. Hot debate even, some might say. I’d like to imagine scientist-fist-fights breaking out regularly over this.** Initially DEET was believed to block insect olfactory receptors, blinding them to human signals. But we now know that insects can indeed smell DEET. Whether they intensely dislike the smell and stay away because of that, or DEET acts as Bug-chaff by jamming signals is a matter that’s just going to have to be settled by fisticuffs.
In the end jammer-blocker-stinker-DEET essentially forces insects into inaction rather than harming them, which compounds moral high-ground on top of DEETs already general badassery. You might have also noticed that DEET has a mini-gun arm, and that’s because shut up.
*some of those may not appear on actual products.
**Whoever wins is correct. Those are the rules of Science-Club.