Obtaining information on wild mammal populations has been a long-standing logistical problem. However, an array of non-invasive techniques is available, including recently developed molecular genetic techniques for the analysis of feces (molecular scatology). A battery of non-invasive, molecular approaches can be used on feces, which in conjunction with conventional analysis are potentially useful for assesing genetic structure, demography and life history of mammals. Several technical problems reman before large-scale studies of feces can be undertaken productively, but already studies are providing insight into population subdivision, food habits, reproduction, sex ratio and parasitology of free-ranging populations.