A recent study published in Urban Ecosystems reveals that urbanization — one of the most dramatic forms of land-use change — may be reshaping how even tiny insects like ants find and accept food. The research, conducted by an international team of scientists from Ukraine, Germany, and Poland, shows that urban ants are far less selective about food quality compared with their rural counterparts, suggesting that city environments exert stress not only on plants and animals we usually notice, but also on insects as common as ants.

The study focused on the common black garden ant (Lasius нигер), one of Europe’s most widespread ant species. Researchers offered ants sugar water at different concentrations in both urban and rural settings and observed how readily they accepted the offerings.

 

The key finding was straightforward but striking: urban ants were significantly more willing to accept lower-concentration sugar solutions, while rural ants mostly rejected these weaker food sources. This pattern emerged most clearly with the weakest concentrations tested, where city ants still readily drank the sugar water while rural ants often ignored it.

According to the researchers, this change in feeding behavior likely reflects broader environmental stress in cities. Urban conditions — from heat islands and soil pollution to microplastics and stressed vegetation — can reduce the quantity and nutritional quality of natural carbohydrate sources, such as the honeydew ants obtain from aphids. If the ants are regularly exposed to less rich food, they may become less selective about what they eat.

 

Tomer J. Czaczkes from Freie Universität Berlin, one of the study’s corresponding authors, explains that ants tend to compare food quality with what they normally encounter in their environment. When city ants are offered a drop of dilute sugar solution, they take it gladly — not because they prefer it, but because they have likely adapted to lower-quality carbohydrate sources in the urban landscape.

One exciting implication of this research is that ant feeding behavior could serve as a bio-indicator for environmental stress. Because ants respond rapidly to changes in habitat quality, tracking how “picky” or “un-picky” they are could offer a simple, low-cost way to assess the health of urban ecosystems.

 

However, the scientists caution that this is a first step. It remains unclear whether the ants themselves are physiologically stressed, whether the plants they rely on for food are stressed, or whether both factors play a role. More research will be needed to untangle these causes.

As cities continue to grow around the world, it becomes increasingly important to understand how urbanization affects biodiversity and ecological interactions. Ants, despite their small size, are key players in many ecosystems, helping with soil turnover, seed dispersal, and nutrient cycling. That their behavior changes in response to city conditions underscores how deeply urban environments can shape life — even at the smallest scales.

 

Source: Stanislav Stukalyuk and colleagues, Urban Lasius нигер ants more readily accept low concentration sucrose solution than rural ants, Urban Ecosystems (2026).