Lezi zikhwama ezihlala isikhathi eside, ezingavuzi zenziwe ngobuchwepheshe be-EPI, okusho ukuthi ziklanyelwe ukuphuka ngokushesha kunezikhwama ezivamile ngendlela evumelana nemvelo yokulahla udoti wezinja.Izikhwama zikadoti wezinja zenza kube lula ukuqukatha ukungcola ukuze ukwazi ukuhlanza isilwane sakho ngokuzethemba.