Yes, the mounds of red fire ants are unsightly eyesores in turfgrass and landscape settings, but more importantly, their inhabitants can be hazardous to anyone who happens to disturb their abode. One fire-ant sting may not be terribly painful, but fire ants tend to attack in large numbers and then sting in unison due to an alarm pheromone. If the person is highly allergic to fire ant stings, the result can be life threatening.
To control fire ants without using pesticides, you can drench the mound with two to three gallons almost-boiling water. Repeat this as often as needed to eliminate the colony. Do not pour bleach, ammonia or gasoline onto the mound, since any of these will contaminate the soil.
Several chemical control options are available. Under dry conditions, baits can be quite effective, but they must be fresh, dry and applied when the ants are out and about, foraging. Contact insecticides (the drenches, dusts and granular products that can be broadcast across the entire lawn) are the best option during rainy spells. No matter which product you use, be sure to read the label carefully and follow its directions.