Toilet paper rolls were used as a substrate for observing foraging activity of Heterotermes aureus (Snyder) and Gnathamitermes perplexus (Banks) in the Sonoran Desert of Arizona. Foraging was minimal during the winter months, increased in the spring, was high but erratic in the summer, and then was moderate again in the fall. H. aureus foraged within a temperature range of 7.6° to 47°C, G. perplexus foraged within a range of 9° to 49°C. Temperature had the greatest influence on the number of foragers appearing at the soil surface. Rainfall (and resulting soil moisture) greatly affected foraging in the summer. Density of H. aureus foragers was estimated to be 4.31 x 106, while the density of G. perplexus was about twice that of H. aureus. Density of H. aureus colonies was ca. 190.4 colonies/hectare with an average of 22,632 foragers/colony and an average foraging territory of 12.5m2. Together, these two species transported soil to the soil surface at a combined rate of 744.2kg/hectare/year. Both species brought up soil richer in clay and added significant quantities of organic carbon, nitrogen, PO4, Na, Mg, and soluable salts, while H. aureus alone increased soil K.

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