Bugspray

You find a box in the attic.

In this box are aerosol cans labeled “Bugspray”.  At the bottom of the can, nestled in the concave niche, is a dial.  The dial has labels for gnat (the dot on the dial is here), dust mite, fruit fly, housefly, black widow, radioactive tarantula, AIDS-III-carrying mosquito, and giant man-eating cockroach.

Pressing down the nozzle releases an angry cloud of gnats, as indicated on the dial.  A warning label on the can states that the can should not be exposed to open flames.