Subterranean termites bring enormous damages on wooden buildings and cultural properties (e.g., ancient temple, historical documents). Due to temperature increase in climate, there is a strong potential for termites to disperse in temperate zone widely. Since subterranean termites construct complex nests, diverging vertically from the horizontal network, we measured “movement efficiency” to address how fast termites pass through the tunnels in different slopes. Artificial tunnels were constructed on observation arena (curvature of 3cm) across different slopes (20o, 40o and 60o between the plate and ground). The passing time of the tunnel by single individual was subsequently measured. When the angle was 20o, there was no significant difference in movement efficiency (7.37 ± 1.07sec) compared with the case without slope (7.84 ± 1.35sec). As the angle was further increased, however, passing time increased. The mean time was approximately 8.79 ± 2.45sec and 14.83 ± 2.479sec at angles 40o and 60o respectively. It was also noteworthy that the termites showed the tendency to avoid entering into the tunnel. Optimization in nesting was further discussed between cost (i.e., energy requirement) and benefit (i.e., foraging efficiency) in tunnel construction.