Its scientific name is Dactylopius coccus. In Spanish it’s grana cochinilla, in English cochineal, and in Náhuatl nocheztli. The Náhuatl name combines nochtli (cactus) and eztli (blood), an apt name for an insect that breeds on Opuntia plant pads and expels a bright red liquid when crushed. The result is a dye that’s been immensely valuable for centuries.

At Nocheztlicalli, the House of Cochineal, you get to learn about this insect’s life cycle, preservation, and uses.

English speakers might recognize cochineal better by commercial names like “natural red 4,” E120, or carmine found in ingredient lists for products like bright red candies and makeup. The Aztec/Mexica people used it to dye clothing. When the Spanish conquered what is now Mexico, cochineal was one of the most valuable exports to Europe.

Europeans primarily used it to color fabrics in several shades of pink and red, including the iconic “red coats” of British armies. This distinctive color comes from the carminic acid found in the insect. For a time, cochineal was known as “red gold,” sharing a similar history with Tyrian purple extracted from sea snails.

In the museum, visitors can encounter living cochinilla being introduced to nopal pads, as well the dried version ground on stone metates to demonstrate pre-Columbian processing techniques.

While “nochtli” means cactus, Náhuatl has another word specifically for Opuntia species: “nopalli.” Known in Spanish as nopal/nopales, this might be the most popular cactus in Mexican culture. Its immature pads are used as a vegetable, while their fruit (tuna in Spanish, prickly pear in English) is also consumed widely. Dactylopius coccus shares humans’ predilection for this plant, as the museum staff use them along with woven “nests” to raise the insects.

The museum’s garden grows nopales and other plants that showcase the ethnobotany of Indigenous peoples including the Aztec/Mexica, Zapotec, and Mixtec. It also shows species introduced by the Columbian Exchange. Dyeing demonstrations include a watercolor session in which cochineal is used for red, the Old World coffee for brown, and other seasonal products—like Tagetes marigolds, known as cempasúchil and representative of Day of the Dead celebrations—make up the rest of the palette.