Don't want to use nasty pesticides in your garden? But also, don't want to have pests eating your garden before you get a chance to? Like most things in life, caffeine is here to save your ass.
Lifehacker clues us in: insects are like dogs apparently, in that they're not supposed to have caffeine.
So this means that on those occasions where I've come back to my desk to find a dead bug floating in my coffee...they've simply had it with life and wanted to end it? Or is getting a bit of awesome brew worth the cost of their lives? Either way, it's slightly morbid and weird. Again, like most things in life.
The other pressing question: can this give your broccoli the kick of a can of Red Bull? And the other other pressing question: apparently there aren't any caffeinated salad dressings on the market. Why not?
P.S. A couple of commenters on the LH site point out that Starbucks will usually gladly hand over their coffee grounds if you don't have any of your own. But of course you have some of your own. How silly.