What if this was at an airport? Someone brings a suitcase full of extremely impregnated mosquitos. Unzips by security and then what? People wouldn’t realize until after. Extended length flights (JFk to OGG) would be so uncomfortable.
Anyone dressing tzniusly would see the hand of Hashem sparing their arms and legs. Bare arms, the first to succumb.
Using pesticides indoors is a health concern of its own.
You can make mace out of any can? Canned yams?