There you are wandering around your yard when all of a sudden, bam! your feet feel like they are on fire.  You look down and see hundreds of fire ants injecting their venom into you and thoughts of grabbing the gas can and torching their mounds sounds like a reasonable idea. Well hold on there, you can't do that.  It is way too dangerous.  Try some of these ecological controls instead.

One of the most effective new biological fire ant treatments is a nematode, Neoaplectana carpocapsae.  In trials, one application of these critters had inactivated about 80% of treated mounds in 90 days.  You may be able to find this control at feed & tack stores or garden supply centers.

Another control said to be successful is to mix together one gallon of orange or grapefruit juice, 2 gallons of water and a dash of dish soap or peppermint soap and dump it on the mounds on a sunny but cool day.

Prevention / Sanitation and Habitat Reduction should not be overlooked.  Remove mulch, food sources (especially cooking oils and grease), garbage, manure, fruits and nuts, debris, pieces of lumber, old equipment, weeds and grass; elevate bee hives; caulk and seal or fill with aerosol foam insulation all open voids, cracks, crevices (in houses, barns, etc.); quickly remove dead animals and hay bales; regularly mow and trim; where you want to keep them out, lightly dust their possible entrances with talcum powder, medicated body powder or Comet® or smear petroleum jelly or Tanglefoot® where you want to capture them and prevent their entry.  You can also use WD40 or vacuum up fire ants where it is not safe to use hot water or other controls.

Natural diatomaceous earth with pyrethrin, e.g., Perma-Guard® can be dumped around fire ant nests to control them.  The diatomaceous earth supposedly scratches the ants' exoskeletons and dehydrates them while the pyrethrin is a natural poison which works to help put out the ants' fire.

A home brewed poison of  sugar, ammonia and pine oil mixed 1 oz. to a gallon and then poured directly on the nest is said to work.

Boiling up a large pot of soapy water (3 - 4 oz. liquid dish or peppermint soap per gallon for a total of 3 - 4 gallons) with one or all of these ingredients: Vitamin C, ascorbic and citric acid, orange juice, pine oil, citrus oils, sugar, white vinegar and ammonia and pouring the mixture on each nest in the yard, repeated daily as needed, is said to be effective also.  The oils in citrus peels are very effective on ants that contact them - but they break down quickly, so cover the nests well with them.

10% sugar and 1% boric acid or borax liquid baits left for the ants to consume may eventually work but this method may take 3 - 4 months to obtain control.

Also try sliced raw fish soaked in a 5% - 10% boric acid bath for 10 minutes.  Or bacon grease which has 1% boric acid or borax liquid added.  Do not apply these baits if the ants are not actively foraging.