In addition to there being no reason to kill them, I haven't figured out an easy way to kill them. The most visible one in Cabarrus County has a black marking that gives the red part a valentine shape. It is called a cowkiller because the pain of a wasp this large should kill a cow. Actually they ants are non aggressive and should be ignored. First be sure you have fire ants.
Fire ants are small reddish-brown ants with very large mounds.
The large mound do not have visible holes but large numbers of ants are quickly visible when the mound is disturbed. There is no way to kill all the ants in Cabarrus County. You will have to drench the individual mounds in the area where you want to control them. Use Dursban, Orthene, or Diazinon. Try to get 2 or 3 gallons of water soaked into the mound.