History and Objectives: Rodents are living in different climates with dispersed and highly populated colonies. Some species share common living space with human beings. Due to hygienic and economic burden of rodent clean up, comprehensive knowledge of their living habits in a given geographic region is of prime importance. The present study was designed to determine the type of rodents and their biological activities in the desert region of Kashan, in 1996.

Materials and Methods: A descriptive study was carried out on wild rodents caught alive in the region. Rodents were hunted by setting live-catching metal traps. Forty traps were employed fifteen day of a month during different seasons of the year. The traps were placed at the entrance of the active holes to hunt rodents. The fauna and their biological activities were studied. In order to determine the type of rodent, biometric measures and key characteristics of rodents were recorded.

Results: From 825 traps, 167 small rodents in 9 species were caught. The majority of the species were classified as Rhombomys opimus (53.3%) and Meriones libycus (31.3%). These 2 groups of rodents were gregarious. R.opimus were active during the day whereas M.libycus were active during night. R.opimus had two peaks of activities. Most of their activity was devoted to summer time with a lesser peak of activity in the end of fall season. The mean body length for the R.opimus and M.libycus were 307 and 292 mm respectively.

Conclusion: Due to the high incidence of and variation of species and their role in the transmission of diseases, recognition of different species of rodents and their biological activity are important in the control of rodents. Therefore further research is required.