Would you eat yogurt made with ants? Scientists did

"Today's yogurts are typically made with just two bacterial strains," says senior author Leonie Jahn from the Technical University of Denmark. "If you look at traditional yogurt, you have much bigger biodiversity, varying based on location, households, and season. That brings more flavors, textures, and personality."

A Forgotten Practice in the Forests of the Balkans

Red wood ants (Formica species) are found throughout the forests of the Balkans and Turkey, where this unusual yogurt-making practice was once part of local culture. To learn how it worked, the research team visited the Bulgarian village of co-author and anthropologist Sevgi Mutlu Sirakova, whose relatives still remembered the process passed down through generations.

According to lead author Veronica Sinotte of the University of Copenhagen, the group followed the community's traditional steps. "We dropped four whole ants into a jar of warm milk by the instruction of Sevgi's uncle and community members," Sinotte recalls. The jar was then placed inside an ant mound and left to ferment overnight. By the next morning, the milk had thickened and developed a sour taste. "That's an early stage of yogurt," she adds. "And it tasted that way as well."

The team described the flavor as mildly tangy with herbal notes and hints of grass-fed creaminess.

How Ants Turn Milk Into Yogurt

When the researchers returned to Denmark, they analyzed what made the process successful. They discovered that ants carry both lactic and acetic acid bacteria, which release acids that cause milk to curdle, much like in commercial yogurt fermentation. One bacterial strain was similar to those used in sourdough cultures.

The ants also directly influence the transformation. Their formic acid, part of their natural defense system, lowers the milk's pH, helping beneficial microbes thrive and improving the yogurt's texture. Enzymes from both the ants and the bacteria work together to break down milk proteins, creating the familiar consistency of yogurt.

Why Live Ants Make the Difference

To better understand the process, the team compared milk fermented with live, frozen, and dehydrated ants. Only the live ants produced the right microbial balance for yogurt to form. Even so, the researchers emphasized the need for care, as live ants can carry parasites, while preserved ants may foster harmful bacteria.

From Rural Roots to High-End Cuisine

To explore modern culinary possibilities, the scientists teamed up with chefs at Alchemist, a two-star Michelin restaurant in Copenhagen. The chefs transformed the traditional yogurt into creative dishes, such as yogurt ice-cream sandwiches shaped like ants, mascarpone-like cheeses with a sharp tang, and cocktails clarified with milk -- all inspired by the ancient recipe and featuring ants as a key component.

"Giving scientific evidence that these traditions have a deep meaning and purpose, even though they might seem strange or more like a myth, I think that's really beautiful," says Jahn.

"I hope people recognize the importance of community and maybe listen a little closer when their grandmother shares a recipe or memory that seems unusual," says Sinotte. "Learning from these practices and creating space for biocultural heritage in our foodways is important."