Skip to Main Content


Imported Fire Ants (IFA)


Imported Fire Ants (IFA) were accidentally introduced into the United States from South America, beginning in about 1918. The first confirmed sighting of IFA in Tennessee was an isolated infestation in Shelby County in 1948, which was quickly eradicated.  Natural migration of IFA was first documented in Tennessee in Hardin County in 1987. Now, much of Tennessee is infested with IFA.  Tennessee Imported Fire Ant Areas by County.

Imported Fire Ants look very much like ordinary ants.  They are between a tenth and a fourth of an inch in size and reddish brown to black in color.  Imported Fire Ants are very aggressive when disturbed and cause a painful sting that produces a small white pustule about 8-24 hours following the sting.

Fire ant colonies build mounds that may be 10 inches or more in height, 15 inches or more in diameter, and 3 feet or more in depth.

A fire ant mound contains a queen (In some areas outside of Tennessee, there may be many queens in a colony), workers, and immatures (egg, larva, pupa). When the colony population is sufficiently large, winged males and females are produced.  At a time of favorable weather conditions, a mating flight occurs, after which the queens that survive begin new colonies. A new colony is generally less than a mile away from the colony of origin, but is occasionally 10 miles or more away.  In heavily infested areas single queen colonies can reach densities of 20-50 mounds per acre.

Contact your County Extension Agent or the Tennessee Department of Agriculture, Division of Consumer and Industry Services, Plant Certification Section for assistance in identifying potential Imported Fire Ants.

Imported Fire Ants cause harm and economic losses in a variety of ways.  Stings from fire ants inflict intense pain to millions of Americans each year with thousands requiring medical treatment.  A small number of people develop a life-threatening allergic reaction to IFA stings.  The number of human fatalities resulting from IFA stings is not known due to lack of documentation.  However, there have been confirmed deaths due to IFA in Texas, Louisiana, Mississippi, Alabama, Georgia, and Florida.  Imported Fire Ants also attack and kill domestic animals and wildlife as well as destroy seedling corn, soybeans, and other crops.  Fire ant mounds can damage farm equipment and lawn mowers.   IFA are attracted to electrical equipment and chew on insulation, resulting in short circuits and interference with switching mechanisms.  Fire ants can shut down air conditioners, traffic signal boxes, and even airport runway lights.  Approximately $2 billion in damage, including costs for insecticide for fire ant suppression and eradication, is caused by IFA in the United States each year.

Imported Fire Ant Quarantine

Imported Fire Ants spread into new areas through natural mating flights and through artificial (man-aided) movement of infested products such as sod, baled hay, soil (alone and with other material), plants (excluding house plants) and used earth moving equipment.  The rate of spread through natural mating flights is relatively slow in comparison to movement through man-aided means.  In 1958, the United States Department of Agriculture, Animal and Plant Health Inspection Service (USDA, APHIS), enacted a  Federal Imported Fire Ant Quarantine (7CFR301.81) to slow the artificial spread of Imported Fire Ants from fire ant infested (quarantined) areas to non-infested (non-quarantined) areas.  The Imported Fire Ant Quarantine includes all of Alabama, Florida, Georgia, Louisiana, Mississippi, Puerto Rico, and South Carolina and parts of and parts of Arkansas, California, New Mexico, North Carolina, Oklahoma, Tennessee and Texas. USDA IFA Map, June 2017.

Within Tennessee, all or parts of 74 counties are quarantined for Imported Fire Ants.  The Tennessee Imported Fire Ant Quarantine Rule was established in 1990.  Surveys are conducted annually to determine the extent of natural northward migration and to increase the quarantined areas when necessary. Tennessee Imported Fire Ant Areas by County.

Materials Regulated by the IFA Quarantine

The following regulated articles require a certificate or permit before they can be shipped outside the quarantined area:

  • Imported Fire Ant queens and reproducing colonies of Imported Fire Ants.
  • Soil, separately or with other things, except soil samples shipped to approved laboratories (consult with a State or Federal inspector for a list of approved laboratories).  Potting soil is exempt if commercially prepared, packaged, and shipped in original container.
  • Plants with roots and soil attached, except house plants maintained indoors and not for sale.
  • Grass sod.
  • Baled hay and straw that has been stored in contact with soil.
  • Used soil-moving equipment.
  • Any other products, articles, or means of conveyance of any character whatsoever not covered by the above, when it is determined by an inspector that they present hazard of spread of the Imported Fire Ant and the person in possession thereof has been so notified.

Requirements for Growers Concerning the IFA Quarantine

Under a compliance agreement, a nurseryman in a quarantined area is required to treat regulated articles with USDA/APHIS approved fire ant control products and procedures prior to shipment to non-quarantined counties.  Compliance agreements are available by contacting Anni Self, Plant Certification Section Administrator, at the Nashville office by e-mail at, by phone at (615)-837-5313, or by fax at (615)-837-5246.

There has been a change in the treatment frequency and technique involving drenching of Balled and Burlapped (B & B) Plants. This information is available in the Related Link – USDA APHIS PPQ Treatment Manual Section on Imported Fire Ant (February 2015). While chlorpyrifos remains the only chemical option and the total volume of the treating solution must be 20 percent (1/5) the volume of the root ball, plants may now be treated only a total of two times in one day with one half the total drench solution for each of the two treatments. After applying one half the total drench solution for the first treatment, there is a required wait of at least 30 minutes and a rotation of the root ball prior to the application of the second treatment. Rotating or flipping the root ball between applications is required to insure all sides of the root ball are sufficiently treated. The USDA APHIS PPQ Treatment Manual may be accessed on the web at

Transportation of Regulated Items From Quarantined to Non-Quarantined Areas

To prevent the spread of Imported Fire Ants regulated items may not be moved from quarantined areas to non-quarantined areas unless accompanied by a document that certifies certain procedures have been met to ensure that these items are apparently free from Imported Fire Ants. A state certificate and/or USDA shield must accompany each shipment.  This would not apply to a homeowner purchasing a plant from their local store.  However, the local vendor in a non-quarantined area should have a certificate stating that the plants have been treated or are apparently fire ant free if they were purchased from a nursery in a quarantined area.  Procedures for the movement of other items such as baled hay differ somewhat.

Consequences of Breaking the Imported Fire Ant Quarantine

Since the Imported Fire Ant quarantine is a federal law, violations of the quarantine are considered federal offenses, and these cases would be subject to federal prosecution.  In addition to this, the Tennessee Department of Agriculture, Division of Consumer and Industry Services, Plant Certification Section has civil penalty authority in Imported Fire Ant quarantine violation cases.

What Can I Do If I Buy Products Infested With Imported Fire Ants?

Contact an office of the Plant Certification Section or your County Extension Agent to confirm Imported Fire Ant presence so that appropriate steps can be taken to close this potential route of infestation.  Consumer education is becoming increasingly important.  Retail outlets and consumers are potential routes of spread of fire ants.  Regulated items can legally be moved within quarantined counties without being treated, but then be purchased by consumers in adjacent non-quarantined counties who inadvertently spread fire ants into their county.  The University of Tennessee Agricultural Extension Service has educational materials available to consumers to assist them in identifying fire ants and minimizing their impact.  They can be obtained at your local county extension office.