9723033 Randall Drumming on the ground to create mechanical vibrations is an important means of communication in open, desert environments, and is widespread among desert rodents. Both solitary kangaroo rats, Dipodomys, from North America and social gerbils, Rhombomys, from Central Asia exhibit footdrummming in the presence of predators. Because this behavior costs time and energy and is dangerous, it must provide some benefit. The objective of this study is to determine why desert rodents place themselves at risk by footdrumming in the presence of predators. Behavioral observations and experiments with snake and mammalian predators in the field will test predictions that solitary kangaroo rats footdrum to communicate directly to the predator that the rat is alert and the predator's chances of successful capture are low, while social gerbils footdrum to warn relatives and offspring of danger. Results of the study will contribute to our understanding of footdrumming as a unique form of mammalian communication and its function as anti-predator behavior in ground-dwelling desert rodents. The study should lead to a greater understanding of how predation acts as a selective force on prey behavior and contribute to recovery programs of endangered species of kangaroo rat.