Chihuahuan desert subterranean termites, Gnathamitermes tubiformans (Buckley) and Amitermes wheelerii (Desneux) readily located surface foods but failed to utilize buried foods of the same type. The termites attacked both natural cowdung pats and artificial (polyurethane) cowdung pats at the same rate as estimated by holes chewed through plastic film barriers placed between the soil and both kinds of pats. There was smaller diel excursion of temperatures in the upper 20 cm of soil under dungpats than in the soil not under dung. We suggest that desert subterranean termites locate relatively large size surface foods such as cattle dung and Yucca sp. logs by sensing the thermal shadows cast by such items.