Why does tequila have a worm in the bottle?

Tequila does not traditionally have a worm in the bottle. The practice of adding a worm is more commonly associated with certain types of mezcal, not tequila. The worm is actually the larvae of a moth that infests the agave plant, which is used to make mezcal. Some believe that the worm adds flavor or has mystical properties, but it is not a common or traditional practice in the production of tequila.