Home range size, overlap and exploitation in domestic farm cats is examined. Data were collected on the 11 adult cats (5 O'O'; 6 ♀♀) living on 3 Swiss farms throughout 1984; 8 of the cats were fitted with radio transmitters. Census-point and focal animal methods of data collection were employed. From area-observation curves we concluded that our home range maps (and sizes) were good approximations of the areas utilized by the animals in 1984. Correlations existed between range size and 1) the number of map-fields visited per day by the cat (+); 2) the percentage of observations at the primary home (-); 3) the proportion of the range visited each day (-); and 4) the percentage of map-fields used only by one cat (+, but only for males). The general pattern of social organization found elsewhere was confirmed: males were generally more tolerant of each other than females (based on range overlap), especially considering animals living on different farms. Animals from the same primary home showed considerable range overlap. Male ranges were much smaller than expected (not even twice as large as the female ranges, whereas they should have been about 10 times the size, based on all other studies). These results are discussed in connection with male reproductive strategies, cat density and patterns of range utilization. And lastly, we could demonstrate coordination of hunting activity in time and space by two adult individuals on one farm (sibs), adding to the list of behavior patterns illustrating facultative sociality of house cats.