Resetting the path integrator during tunnel excavation by the Formosan subterranean termite (Isoptera: Rhinotermitidae)

Subterranean termites excavate tunnel patterns that radiate outward from a point of origin along vectors generated by path integration. Upon encountering wood or open space they reset their path integrator and re-radiate away from that point, leading to complex search patterns. In this study we forced termite excavators to travel through a tube with a 90º bend before entering a sand-filled arena, an opened chamber with perpendicular openings that forced a 90º turn prior to access to the arena, and an open chamber with an odor trail layed down by previous termites travelling through the opened chamber joining the perpendicular openings. We found that termites responded similarly when a path is demarcated by either tube or odor trail, suggesting that they are not responding to a cue derived from an intrinsic value of open space. Instead, the discontinuation of their perceived path as they travelled through the open space caused resetting of the path integrator.