These insects are able to swarm their victim, then signal each other to bite simultaneously. It's quite common not to know they are on you until you're being bitten in several to dozens of places at once. Over 260 million acres in the United States are infested with these opportunistic ants as they drive out, or kill, native ant species. Crop producers lose upwards of two billion dollars due to fire ant damage each year. Quarantines are placed on infected crops preventing their sale or export to uninfested countries.
Ants eat and destroy a wide variety of fruit and vegetable crops.
Fire ant mounds can be enormous. It used to be that each nest had but one queen, buried up to 25 feet underground and supported by a complex network of other ants performing an amazing array of tasks. Now mounds are often found with multiple queens, presumably as a reaction to chemical pesticides. Those queens willing to share have more successful colonies since it is harder to kill multiple queens than just one, and therefore their genes are passed along to their offspring. Worker ants live only a few months, but the queens live two years, producing about a thousand eggs a day.