Unless you're an eremite on top of pole in the Syrian desert, you probably do consumer stuff. We buy stuff, we use services. I'm going to start reporting on stuff I've bought that has worked, or hasn't. It's only an N of one, but by god, it's my N. "Maybe this isn't the most important foxhole in the war, but I'm in it!"
First up: killing yellow jackets, aka hornets.
Google ways to kill yellow jackets, and you will probably hit this page, from the Alaska Outdoor Journal, which suggests that a trap that looks like this:
The web page airily reports that, "It only takes a day or two to wipe out nearly every yellow jacket in your area."
It doesn't work.I don't know whether there's something about creationist, pro-life, pentecostal, moose-stinging, Matanuska Thunderfuck-smoking Alaskan yellow jackets that makes them susceptible to fish traps, but my local Prius-driving, Timbuk2-carrying Philly suburbs yellow jackets are utterly unimpressed.
I made a trap just like that photo, and tried it three times, within 1-3 feet of two active yellow jacket nests. Twice I got nothing. Once I got three yellow jackets. Once the fish was stolen by some four-pawed denizen of the night, probably a raccoon. Complete waste of time.
Similar idea, using a soda bottle and jam.
Also doesn't work.What does work?
About US$7 at my local Acme. Go out early in the morning, when it's still cool and the yellow jackets aren't active yet, get as close as you dare, and spray the whole thing in the hole. Check in a day or two, and if there is still activity, spray again. End of problem.
Pouring gasoline down the hole also works, and is cheaper, but when the hole is horizontal, in a bank, it can't be easily done, and if there are plantings nearby, they may be killed. BTW, don't light the gasoline, it's dangerous and unnecessary, the fumes alone do the job.