Finding shortcuts through collective tunnel excavation in a subterranean termite

Facilitating efficient resource transfer requires building an optimized
transportation network that balances cost minimization with benefit
maximization. For animals that forage for food located remotely,
optimizing their transportation networks is critically related to
survival. This process often involves finding and using the shortest route
to save time and energy. Subterranean termites forage for wood resources
by excavating underground foraging networks for search and transport.
Because termites have no prior knowledge of food location during the food
searching phase, establishment of a short tunnel between the nest and
feeding site is difficult at the beginning of foraging. Thus, finding a
short route should logically follow initial food discovery. However, it
remains elusive as to how subterranean termites find the shortest route
for food transportation. We simulated different scenarios using
Coptotermes formosanus by providing different shapes and distances of
pre-formed tunnels (straight, detour, and detour + twisting arenas) to
food, where food items were located at a fixed distance from the arena
entrance. Termites in the straight arena continuously used the pre-formed
tunnel, showing negligible branching efforts. However, termites in the
detour and detour + twisting arenas followed the pre-formed tunnel only
for the initial few hours before excavating many branching tunnels. This
branching activity ultimately resulted in termites finding shorter
commuting routes than the pre-formed tunnels. In addition, the shortest
established routes were widened over time. This study demonstrated that C.
formosanus could actively alter tunnel networks to minimize the cost in
food transportation by using short and wide tunnels.