Two weeks ago, we received a FedEx package containing two poly bags filled with what looked like grains of rice and seed hulls. After one afternoon in our entryway, they smelled awful, like some kind of feces rolled in mothballs.

Turns out the "rice" really was some kind of shit, containing enough organic matter to sustain thousands of quarter-inch wasps we had ordered to combat the fly infestations of late summer.

Any cattle producer will tell you flies are the root of worry when it comes to profit and loss, as big a menace as bad weather. They're vectors for all kinds of infection, mostly pinkeye, and cause even well-adapted herds unrelenting stress for several weeks in late summer. Stand long enough to watch the animals, and you'll see that their will to shed the crawling, biting pests is broken by mid-August. They let them stick and swarm around their eyes, on their noses, in their ears, along their backs and bellies, and on their assholes, udders and other private parts. I'm not sure I'd be interested in eating or drinking or breeding with that number of feet stomping around on my most delicate skin, either.

There are, of course, hundreds of toxic products on the market to kill flies and prevent their attraction to livestock. The most common applications are insecticides poured directly on individual animals corralled in a chute or spritzed automatically when animals help themselves to salt licks, water tanks, or mineral tubs.

The wasps (insert Latin) fall in the integrated pest management category. This ground-creeping species lays its eggs in, on or near fly larvae, which its own larvae devour. It's a bloody mess down there at ground level, but it does cut down on the number of adult flies pestering the herd. In theory.

I spread our two bags of bugs by walking among the cows as they stood in their preferred afternoon shade, half-heartedly stamping, sweat glistening. The adults wasps aren't big enough to cause a human much sensation when stung, so they're easy to distribute. "Open bag and spread by hand," the packaging stated.

I felt a little like I was salting about two square feet of a square mile, but I did saturate an area I know to be heavily used by the herd. If, next time you're by the farm, you see me on my knees slicing open cow pies looking for insect carnage, you'll know why.