CAREER: Linking Form and Function in Fire Ant Architecture

Emory University, Atlanta GA

Investigators

Abstract

Red imported fire ants are robust and adaptable social insects that excavate large below-ground nests composed of dense networks of tunnels and chambers (a large colony can contain hundreds of thousands of ants, and a large nest can be several feet deep). These ants are highly invasive; originally native to Brazil, they have been inadvertently transported via ships across the globe and have established footholds in North and Central America, several Caribbean islands, Asia, Australia, and have very recently (as of September 2023) been found in Europe. Studies over the past several decades have noted their significant negative impacts on the health and diversity of local wildlife (including crops and livestock) and their great potential for further expansion, making them the focus of many failed eradication attempts since their introduction into the US nearly 100 years ago. While nests are crucial for a colony's survival, nest size and soil opacity have prevented detailed investigation or theoretical understanding. In this project, the PI will use experimental and computational techniques to establish links between the nest structures, functions, and organization in the red imported fire ant by focusing on the following questions: (1) what can be inferred about below-ground nest structures from above-ground dynamics? (2) how are subterranean nests organized? and (3) how do environmental factors influence subterranean nest networks? A new experimental technique developed in the PI’s laboratory will provide, for the first time, spatially resolved quantification of the internal structure and organization within large-scale natural and lab-created nests. Though most of the nest is below-ground, a mound is created atop the nest through the repeated placement of soil pellets above ground. A custom-built surface scanner provides quantitative three-dimensional data of the above-ground mound formation dynamics that accompany nest construction. This combined approach provides the first ever data of this kind and will help elucidate the physical and biological principles underlying natural nest construction, organization, and adaptability in a highly successful species of master builders. This project will also support a newly established outreach partnership with The Girl Scouts of Greater Atlanta will actively engage young girls, a traditionally underrepresented group in physics, in exciting concepts, techniques, and results at the interface of physics and biology. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.