Exploring the world’s deepest caves is often described as the subterranean equivalent of climbing the highest mountains. It’s an apt comparison,as there are more than a few similarities between speleological expeditions and high altitude mountaineering. Both typically require vertical climbing, for instance, and both manifest the ever-present threat of falling to one’s death, being crushed by rock (or ice),or getting swept away by a flash flood (or avalanche). But if anything, venturing deep below the earth’s surface is even more stressful, because caves are invariably dark, wet, and drafty (imagine being sequestered in a pitch-black room, soaking wet, with an air-conditioner blowing on you, for days or weeks at a time), and often deafeningly loud (imagine the sound of a thundering waterfall confined to an enclosed space). Never mind the often unseen threats—rabid bats,venomous snakes,fist-sized spiders,and microbes that cause horrific afflictions like histoplasmosis and leishmaniasis.
From this microbial soup, fibers begin to sprout and propagate, eventually resulting in thin, wet sheets of bacterial cellulose that can be molded to a dress form. As the sheets dry out, overlapping edges “felt” together to become fused seams. When all moisture has evaporated, the fibers develop a tight-knit, papyrus-like surface that can be bleached or stained with fruit and vegetable dyes such as turmeric, indigo, and beetroot.
Although the scientists only tested the visual attractiveness of the moustache, they strongly suspect it also has a tactile function. “This is based on the general observation that males will touch the female’s genital region with their mouth prior to mating,” Prof Schlupp told the BBC. This behaviour is known as ‘nipping’ and is being investigated further by the scientists. But they think that the females can acquire information about the males this way. In short, rubbing his moustache against a female’s genitals may be a way for a male Mexican molly to advertise his attractiveness.