Tunneling activity of subterranean termites (Isoptera: Rhinotermitidae) in sand with moisture gradients.

Tunnel formation by Coptotermes formosanus and Reticulitermes flavipes was studied in a two-dimensional foraging arena with a moisture gradient. Moisture did not appear to affect tunneling when termite first emerged from the central release chamber. But as termites of both species moved further away from the chamber and into a moisture gradient, they tunneled significantly (P < 0.05) more in sand with a higher moisture content than in sand with a lower moisture content. Over the 10 d test period, both termite species tunneled more in sand with a higher moisture content. Fractal analysis indicated that regardless of the sand moisture content, termite tunnel geometry had a fractal dimension and termites generally tunneled more in higher moisture sand.