Whereas the bush pig is active at night, preferring the denser bush, the warthog, being more diurnal, is seen more frequently in the open during day.  When feeding the warthog frequently drops down on its knees to uproot bulbs and tubers, or to feed on its preferred diet of short, green, lush grass.  When alarmed it trots off, head and tail carried high.  One question, puzzling scientists and others alike, is why the warthog invariably erects its tail when running.  Maybe the warthog, with this strange behavior, is desperately trying to point out to mankind, that every act does not necessarily have to be explained!  Fleeing from its enemy the warthog makes for the nearest ant-bear hole, quickly wheeling around when reaching it to enter backwards.  And woe betide the dog that dares to attack a warthog, especially when wounded.