Measurement of Time Taken by the Formosan Termite, Coptotermes formosanus, to Pass Tunnel Intersections

Subterranean termites build complex tunnel networks below ground for foraging. During the foraging activity, termites may encounter a considerable number of tunnel intersections. When they encounter the intersections, they spend some time gathering information for making a decision regarding their moving direction by anntenation. The spent time is likely to be directly connected to the termites' survival because depending on the time, the total traveling time taken by the termites for transferring food resources from the site of food to their nest can vary significantly because of many intersections. In the present study, we measured the time spent by a termite to pass an intersection with widths of W(1) and W(2) (W(1) and W(2): 2, 3, or 4 mm); τ(L), τ(R), and τ(s) are the passing time for turning left, turning right, and going straight, respectively. W(1) represents the width of the tunnel in which the termites advanced, and W(2) represents the width of the other tunnel encountered by the advancing termites. For the combinations of W(1) and W(2), (W(1), W(2)) = (2, 2), (3, 3), (2, 3), (2, 4), (3, 4), and (4, 3), the values of Tτ(L), τ(R), and τ(s) in each case were statistically equal. For (W(1), W(2)) = (3, 2), (4, 2), and (4, 4), τ(s) was shorter than τ(R) and τ(R) in each case. The experimental results are briefly discussed in relation to the termite foraging efficiency.