The form of social insect nests
Termite nests have complex and different forms, ranging from structures mainly composed of galleries and corridors, to bubble-like or sponge-like structures, to extremely regular structures, with floors and ramps, to convoluted surfaces used to cultivate mushrooms.
These structures are characteristic of the species that produced them; however, we also find strong analogies between structures produced by phylogenetically unrelated taxa, suggesting that behavioural rules coded in the genome interplay with physical constraints imposed by the building material and environement.
Computer tomography
Computer tomography is a powerful tool for the characterisation of complex 3-D structures.
- It is non-destructive: the same structure can be scanned several times. Also nests still inhabited by insects can be tomographied
- It is quantitative: the size and position of individual elements can be recorded with high accuracy
- Provides data in a digital form, that can be automatically processed. This is essential, as the complexity of these structures is such that they would otherwise be difficult to analyse.
The internal transportation networks
One approach is to consider nests as 3D networks, with nodes (chambers and galleries crossroads) and edges (galleries) that can thus be described by graphs.
This description gives access to the tools developed in the field of graph theory to analyze the material and information flow, and to study the efficiency and robustness of these communication networks in relation to their topological and geometrical properties.
In addition, it becomes possible to perform direct comparisons with other natural and artificial communication networks.
Related scientific publications
- Perna et al. "From local growth to global optimization in insect built networks". in "Biologically Inspired Networking and Sensing: Algorithms and Architectures" (2011) [Pdf] [Web]
- Valverde et al. "Percolation in Insect Nest Networks: Evidence For Optimal Wiring". Physical Review E (2009) [Pdf] [Web]
- Perna et al. "The structure of gallery networks in the nests of termite Cubitermes spp. revealed by X-ray tomography". Naturwissenschaften (2008) [Pdf] [Web]
- Perna et al. "Topological efficiency in three-dimensional gallery networks of termite nests". Physica A (2008) [Pdf] [Web]
- Perna et al. "The topological fortress of termites". LNCS (2008) [Pdf] [Web]
See also
- Slides of a presentation on termite nest networks: [IEC Rennes 2009]
- A website about the structure of termite nests (mostly in French): [www.mesomorph.org]
- An article for the general public about social insect nests: [in French] [in Spanish]