Agenda

Termites build complex nests which are an impressive example of collective behaviour and self-organisation. We know that the coordinated actions involved in the construction of these nests by multiple individuals are primarily mediated by signals and cues embedded in the structure of the nest itself, rather than through direct interactions. However, to date there is still no scientific consensus about the nature of the stimuli that guide termite construction, and how they are sensed by termites.
In this talk I will present evidence suggesting that termites respond to the local curvature of nest surfaces to guide their building activities: high-curvature regions are typically associated with the tips of pillars, or with the edges of a wall. Hence, consistently focusing building behaviour on those regions potentially allows building both pillars and walls, two common ""building blocks"" of the nests of many termite species.
I will also present experimental evidence indicating that termites may not need to sense curvature directly. Instead, they could sense the evaporation flux (and the associated gradient of humidity and temperature) which covaries with curvature (evaporation is faster from high-curvature regions).
Overall, these results point to surface curvature as a sufficient cue, capable of organising termite building activity, and indicate that this is at least one of the cues that are also used by termites, who likely sense curvature through its effect on the evaporation flux."