Self-Organized Linear and Helicoidal Ramps in Insect Nests

The nests built by termites of the genus Apicotermes present a regular succession of floors interconnected by vertical passages. By scanning these nests with X-ray tomography we observed that two different configurations of vertical passages coexist: ramps and helices. Based on our current knowledge of the mechanisms of nest building behaviour in different groups of social insects we formulate hypotheses about the mechanisms that could lead to the formation of these structures. In particular, we show that a 3D model of nest building in Lasius niger ants (Khuong et al, 2016) is capable of producing layered structures with vertical helices similar to the structures built by Apicotermes by simply running it with parameters different from those empirically measured for ants. It is possible that similar self-organised building mechanisms underlie the construction of the different nest structures produced by different groups of social insects.