There's a saying that wherever you go, you leave a part of yourself behind. In my years of tramping around in "the field" as a zoologist, I've come to accept the literal interpretation of this sentiment, allowing bloodsucking insects, skin-searing stinging plants, flesh-ripping thorn trees and the like to extract Mother Nature's toll. But nothing prepared me for the unbridled avarice of the Australian rain forest leech.

Said leech is a particularly artful little rain forest dodger that perches on vegetation, waving its wiry, inch-long, racing-striped body in the air for weeks and even months at a time, waiting for an unsuspecting bag of blood to come hopping, walking or crawling by. Then it frantically hops aboard its unsuspecting host and, with once-in-a-lifetime desperation, wiggles its way to a warm, dark nook, where it bloats itself with a blood banquet. Needless to say, it's one of Australia's animal wonders you don't want to encounter.

My friend Patricia and I weren't thinking about leeches when we planned our visit to New South Wales' Mount Warning National Park. This trip was to be lyrical, inspirational. In a mile-long walk to the top of what was left of this long-extinct volcano, we would pass in rapid succession through wet eucalyptus woodland, subtropical jungle and temperate rain forest. We would see some of the finest floral and faunal diversity Australia had to offer -- a rain forest tour de force that was to be the highlight of our month-long tour of the spectacular national parks of New South Wales.

It had been unseasonably wet throughout our trip, and it was raining again as we approached a brooding Mount Warning. But we were determined to experience the magnificence of the rain forest, foul weather or fair, so once at the trailhead, we suited up with grim determination.

In a steady downpour, I ran the 150 feet from the car to a trail marker in the forest, confirmed our map position and ran back -- a round trip of about 90 seconds. At the trailhead, Patricia took one look at me and exclaimed: "You've got a leech on your pants!"

"So do you!" I yelped, and whacked her savagely with my map.

It took us only a second to realize that our lower extremities were covered with famished leechlets frantically inching upward. The road was suddenly alive with the wiry little devils, all making their way toward us from the surrounding vegetation. In a mad fandango, we began ripping off our clothes, flicking and whacking wigglies off one another, all the while bellowing primal anti-leech epithets.

Heaven knows what the carload of seasoned, bush-savvy locals who pulled up just then thought we were up to. As we stood there half-naked, their car doors opened and a wall of cannabis smoke hit me like a wet pillow.

"How's the trail?" one of them drawled. "A bit leechy," I muttered, gathering up my discarded clothing and trying to muster some composure.

"No worries, mate," he smirked, and rejoined his group, saying something that made the others look at us and laugh. They got out of their car and turned toward the trailhead, confident, barefooted. Patricia and I were skulking away when we heard their panicked shouts: "Leeches, leeches!!"

Our departing vision of the rain forest was of six leech-stricken locals fandangoing at the trailhead. Patricia and I exchanged knowing smiles. "A bit leechy," she said. "No worries," I said, and gunned the car toward the dry eucalyptus forests on the other side of the mountain.

Miles Roberts is a zoologist (type AB-positive) working in Washington.