Building Your Home One Grain at Time: How Construction, Function and Robustness of Fire Ant Nests Depend on Ground Properties

Georgia Tech Research Corporation, Atlanta GA

Investigators

Abstract

In this project the PIs will use laboratory experiments and simulations to systematically study how the behavioral and physical interactions of fire ants (Solenopsis invicta) with cohesive granular media influence the formation of underground nests. The specific objectives are: (1) To study how ant colonies build and respond to perturbations in different media. (2) To understand how ground properties affect nest structure and stability. (3) To study multi-agent simulation models of nest formation. A major problem in modeling nest construction is that the physics of cohesive soils is not sufficiently developed to predict stability of structures. To address this question the PIs will combine information from the first two aims into a multi-agent simulation to model nest formation; individual behavioral rules will be derived from observations and cohesive soil rule will be derived from physics studies. These will be integrated to form a minimal physical model using granular physics simulation and ant grain interaction that captures the observed nest formation and allows the testing of different hypotheses of colony function. The PIs will coordinate with high schools serving populations underrepresented in the sciences to recruit teachers into the research labs and place graduate students into local high schools as teaching assistants. In addition they will also institute engineering-science team projects for undergraduates so that students gain a better understanding of interdisciplinary research at the intersection of biology and physics. The proposed experiments and models can aid in controlling invasive species such as S. invicta by learning how soil modification affects nest building. The multi-agent simulations will be of use to many outside this field for solving scientific or engineering problems. In addition this research program will provide a platform for modeling bioturbation, a major factoring affecting planetary ecology.