Neither scorpion nor spider, uropygids occupy a minor branch of the arachnid tree, with just a single family, 16 genera and slightly more than a hundred named species. In profile, they resemble their venomous cousins, with a low-slung torso and implements of menace on both ends of the trunk. But instead of tapering to a bulbous sting, the rear of the abdomen, which is visibly segmented into sclerotised plates, is attached to a short, cylindrical pygidium and a long, thin flagellum. Though regarded as homologous to the telson of true scorpions, the latter organ is innocuous, being loaded with receptors attuned to airborne currents. The filament is sensitive to faint shifts in ambient pressure, be it from a mild draft or the approach of another body, and can be directed towards the source of the disruption. With tactile aid from the antenniform forelegs, the animal can determine if the stimulus is a possible food source or putative foe. The former are grasped by a pair of moveable fists and ground up between fearsome trochanters, enlarged basal segments of the palps armed with strong teeth on their inner edge.
Inedible threats are met with evasive action, in a quick slide into rocky cracks or the hollows of a dead tree. Cornered individuals, however, are likely to unleash an arsenal of tart secretions from glands on the final segment of the pygidium. This cocktail of water with acetid and caprylic acids, the latter functioning as a surfactant boosting dispersal and settlement, is squirted as fine droplets that establish a broad perimeter of pungency around the uropygid and stick to skin for hours after a taste of its whip. Effective on both vertebrate hunters as well as spineless armies, the spray can be precisely aimed by a revolvable knob.
In jungles where the canopy is closed and the trails are kept wild and wet by thick growth and untamed streams, vinegaroons are not uncommon on mature trunks and earthen mounds. Local forests, in their state of fragmentation and exposure to human elements, appear more inhospitable to whipscorpions, which lack the ability of other arachnids to withstand dessication. Two genera, Thelyphonus and Ginosigma, are known from Singapore, but little else has been recorded about these creatures, which lurk in damp corners of degraded woods, under logs, in root tangles and within deep outcrops, emerging only in the dark to search for, preferably, soft-bodied arthropods. Mostly harmless yet miserably absent in the minds of nature lovers with eyes only for the big, beautiful and bad, these unwholesome beasts enjoy not a whiff of attention from the champions of clean parks and green lawns where the true nature of the earth is kept at bay and mown into perpetual submission.