Non-native Florida ground ant species recruit workers from other nests, revealing new dimensions of invasive ants in mixed landscapes
Researchers in the United States have observed that ground-dwelling ant species from Florida sometimes pull workers from different nests into their colonies. This nuance adds depth to our understanding of how invasive ants establish a foothold in new environments. In the southeastern United States, ant communities form a web of interactions across urban, agricultural, and natural settings, where each landscape shapes how species compete and cooperate.
Lead scientist Andrew Suarez points out that earth ants are very small, with bodies measured in millimeters. As these workers move through soil, leaf litter, and other ground debris, their task feels like a climb up miniature hills. Many of these ground-dwelling ants specialize as predators of small arthropods, including various bowtails, and they contribute to the broader soil ecosystem by recycling organic matter and helping to regulate pest populations. Through foraging and predation, these ants influence nutrient cycles and microhabitats beneath trees and other vegetation.
To learn how different species respond when forced to share a single nest, researchers designed an experiment that mimicked mixed-species colonies. More than 300 living ant colonies were collected and housed in artificial nests. By introducing individuals of the same species from different colonies into a single nest, scientists could observe whether foreign workers would be accepted into the colony’s social structure or faced rejection. This setup provided a controlled way to study social tolerance and nest integration across species boundaries.
The results showed a clear asymmetry: most non-native species could recruit and integrate workers from other nests, while many native ants rejected unfamiliar individuals from different nests. This pattern of tolerance among non-native ants may confer a strategic advantage. By connecting colonies from different nests, non-native ants can operate as a cohesive unit spanning a larger geographic area than any single nest could achieve alone.
As these non-native ants spread, their ability to assimilate workers from multiple nests can speed up colonization, alter competitive interactions, and influence the structure of local ant communities. The findings highlight how social plasticity within ant species contributes to invasion dynamics, where a flexible network can respond to changes in resource availability, predator pressures, and human-mediated transport. In the American Southeast and broader North American contexts, these dynamics are relevant for natural ecosystems and urban-adjacent habitats where human activity introduces new ant lineages.
Current statistics indicate that non-native ants make up about 30 percent of the roughly 177 terrestrial ant species recorded in the region. The majority of these introductions are linked to commercial shipments, including movement of soil, plant material, and consumer goods. The resulting patterns of spread raise practical questions for land managers and researchers who monitor biodiversity, pest management, and ecosystem services. Understanding the social strategies that allow invasive ants to coexist with multiple nests sheds light on why these species can become persistent competitors and how their presence reshapes food webs, soil structure, and plant interactions in affected areas. Attribution: University of Illinois at Urbana-Champaign researchers.