At the bottom of some mezcal bottles sits one of the most recognizable curiosities in the world of spirits: a pale, curled "worm" preserved in alcohol. It has helped give mezcal an air of mystery for decades, but scientists have now shown that this famous bottle stowaway is not a worm at all. Mezcal is a distilled drink made from agave, the same plant group used to produce tequila. Most bottles are sold without anything added, but a small number contain larvae known as gusanos de maguey (Spanish for agave worms). The tradition feels ancient, but it is actually much more recent than mezcal itself. While mezcal production reaches back centuries in Mexico, the practice of placing larvae in bottles appears to have begun in the 1940s. A Longstanding Mezcal Mystery For years, the true identity of these larvae remained uncertain. They had been described as moth larvae, butterfly larvae, and even weevil larvae.…