This article may contain one or more independently chosen Amazon affiliate links. See full disclosure.
I remember a scene in the movie Poltergeist II where Craig T. Nelson’s character is chugging (yes, chugging) a bottle of Tequila. Or was it Mescal? At the bottom of the bottle was a big worm. It reminded me of the catawba worms we used to use as fishing bait, back home. When he reached the end of the bottle, he let the worm slip right down his throat. Even as a kid I remember thinking, “what kind of idiot would eat that thing.” Of course, I knew something he didn’t. The worm was not a regular worm but was some monstrous creature. And it was alive. The character thought nothing of the worm being there because that is normal for tequila. Or is it? Is the movie accurate?

The Agave Worm or Maguey
The notion that it is traditional to put a worm in bottles of tequila is widely believed. The worm in question is said to be the agave worm, which is also called the maguey worm or gusano de maguey (gusano is Spanish for worm).
It is also sometimes called a mescal worm. This is not really a worm but the larvae of a large butterfly. Tequila is made with agave and the larvae feed on the plant, so an association between the larvae and the spirit is not surprising.
Why Put a Worm in Tequila?
It is said that this worm is added to the bottle to prove the quality of the tequila and demonstrate that it contains the amount of alcohol it should. In other words, it is evidence of the tequila’s proof. Simply speaking, if the alcohol content wasn’t high enough, the worm would rot. If the worm is intact or fresh, the tequila must be the real thing!
Tequila Versus Mescal
It is ironic that a worm should be thought to be a proof of tequila quality as tequila quality is tightly controlled by government regulations. A bottle of tequila with a worm in the bottom would not meet these quality controls.
Mezcal (or mescal), on the other hand, is not subject to such stringent guidelines. While tequila can only be made from the blue agave, mezcal can be made from other varieties of agave, including the wild tabala variety. This is not meant to bash mezcal or to turn you away from trying some. It’s bolder than tequila with more heat, but the flavors can hit you in the face, something I appreciate.
Mescal Has a Worm but Tequila Doesn’t?
So, the usual explanation is that mescal sometimes has a worm in the bottle but tequila never had any worm. To further bolster tequila’s non-worm reputation, a story is told of a young boy who had the idea of putting a worm in bottles of tequila as a marketing ploy, one that was so successful that to this day people still think it’s standard practice.
It’s all very murky. Who was this boy? What brand of tequila was he inspired to help market? 1Greene, Granville, and Jack DeLap. The Mezcal Rush: Explorations in Agave Country. Counterpoint, 2017.
Tequila is a Mescal
The truth is a bit less dramatic. Tequila and mescal are often talked about as if they are too separate spirits or kissing cousins. In reality, tequila IS mescal. Or, rather a type of mescal that is produced in specific regions and which now enjoys official government designation and regulation.
It is often said that tequila is to mescal as cognac is to brandy. So, all tequila is mescal, but not all mescal is tequila. Mescal refers to the entire category of agave-based spirits produced from roasted agave.
A Worm Was Traditional in Some Mescales
Traditionally, some mescales had a worm in them, the aforementioned larvae, and some bottles still do. You won’t find many of them at your local liquor store, if any. Being that tequila is a type of mescal, then it is quite possible that some bottles of tequila may have also contained a worm at some point.
At first, this was a mark of “quality” and intended as evidence of the liquor’s proof, as already stated. But, as tequila, and then, to a lesser extent, mescal, moved uptown, the worm did become more of a marketing gimmick.
Lower quality mescales or “con gusano” mescales would use the worm to attract tourists who were easily duped into believing the worm was cultured and hip, marking you as a connoisseur. In general, if you see a worm, expect low quality, although exceptions do exist, such as [https://www.wahakamezcal.com/our-mezcal/ Wahaka Mezcal Reposado con Gusano], which is aged in re-charred oak barrels along with agave worms.
The worms are there for, can you believe it, flavor. An earthy, licorice, and bacon flavor (and smokey), according to the founder. The worms are also claimed to be used for “smoothing out the rough edges of the high alcohol content.”
In this case, the worm is definitely not a marketing gimmick, but whether it improves the flavor is a matter of opinion. Keep in mind that this is an aged mescal (reposado refers to a medium-aged spirit) and the oak barrels will impart flavors.
Personally, I am not a fan of mescals (tequila or not) aged in oak barrels as I do not think the flavors that are imparted work and I would encourage you, if you are new to mescal or tequila, to first try a high-quality blanco (non-aged or white) before jumping to aged varieties.

Agave Worms are Eaten in Mexico
As for those agave worms, they are edible and are regularly eaten in Mexico. There are two varieties, a red and a gold. The red larvae feed on the heart of the agave, the part that is roasted and turned into mescal.
The gold or “gusano de oro” feed on the leaves. The red are considered superior, both for eating and for plunking into bottles. If left to mature, they become a Mariposa butterfly. 1Janzen, Emma. Mezcal: The History, Craft & Cocktails of the World’s Ultimate Artisanal Spirit. Voyageur Press, an Imprint of The Quarto Group, 2017.
Mescal Moves Uptown, Slowly
But tequila has become much too up-scale to be associated with any creepy crawly things. Mescal in general is limping along to its own high-class status. Expect to see mescales in ultra-fancy bottles that jack up the price by at least 50%, any time now. 1Luntz, Perry. Whiskey & Spirits for Dummies. Wiley Pub., 2008. 2Hartung, Tammi. Cattail Moonshine & Milkweed Medicine: The Curious Stories of 43 Amazing North American Native Plants. Storey Publishing, 2016. 3DeLove, Chandler L. Bartending for the Professional and Home Entertainer: No Experience Required, Make Money Making Drinks. IUniverse, Inc., 2004. 4Weir, Joanne. Tequila: a Guide to Types, Flights, Cocktails, and Bites. Ten Speed Press, 2009.