Many moons ago, man lived naked under the sky, happily scratching in
harmony with all of nature. Then he observed the beasts of the herd,
flicking their tails to chase away flies, and the beaver, building
dams to provide shelter and sustenance. And man said, "Let's build
houses with window screens to keep out these damned flies, and maybe a
garden and some chickens out back." And so they did.

Later, man observed plants that killed attacking insects by exuding
noxious juices. He said, "Hey, let's put some of that juice around the
house to get rid of the damned roaches and bedbugs." And so they did.

And he observed cats eating grass and barfing up hairballs, and said,
"I don't feel so well wyself."

It all went downhill from there.

Bill