Ecological drivers for the absence of task shifting in termite-tunneling activity: A simulation study

Subterranean termites build complex underground tunnel networks to efficiently gather food. Empirical observations indicate specific individuals are dedicated to tunneling, rarely interchanging tasks. However, considering the limited tunneling energy of termite populations, it is reasonable to expect regular task shifts between fatigued and rested individuals to maintain continuous tunneling and optimize foraging. To explore this disparity, we developed a sophisticated individual-based model simulating the termite tunneling process in two scenarios: one with task shifting and one without. In the task shift scenario, the initial group of termites excavates the tunnel, expends all their energy, and returns to the nest. A new group is then deployed to the tunnel tip to continue the excavation, collectively creating the final tunnel pattern. In the no task shift scenario, the initial group completes the tunneling without transitioning to subsequent groups. We compared the tunnel patterns of these two scenarios, focusing on tunnel directionality and size. The comparison revealed statistically no significant difference in tunnel directionality between the scenarios. However, the tunnel size was notably larger in the absence of task shift, suggesting that continuous tunneling without task shift may enhance food searching efficiency. In the discussion section, we briefly address the limitations of the model arising from differences between the simulations and actual termite systems. Additionally, we touch on the idea to explain the fact that only a fixed proportion of workers in a termite colony participate in tunneling activities.