Red Imported Fire Ants Bite and Sting

Red Imported Fire Ants
Bite and Sting
By Joe Wolf
Polk County Master Gardener
Anyone who has lived in Florida long and done anything
outside has been introduced to the red fire ant. Usually
people find out after they have been stung and the pain does
not go away for weeks. There are two invasive fire ants here
in this part of Florida: the Imported Red Fire Ants (Solenopsis
invicta) and the Little Fire Ant (Wasmannia auropunctata).
Both are reddish brown in color and live in colonies or
mounds of hundreds of thousands of workers. All of these
A large and a small fire ant
ants sting as well as bite.
The red fire ant is an invader probably brought here as part of a ballast for a ship at either the port of
Mobile, Alabama or Pensacola, Florida sometime between 1933 and 1945. Since that time they have
spread over the entire south as far north as Maryland, Virginia and Tennessee and west to New Mexico
and the San Francisco Bay area of California. The mounds are seldom over 18” in diameter at the
surface and often hidden under rocks, logs or sidewalks. Workers vary in size from less than a tenth of
an inch to about ¼ inch. These ants are predators eating small animals such as crickets and other
insects. They will also eat sweets such as plant sap secreted by sap-sucking insects like aphids and scale.
Unlike other social insects like bees they can have multiple queens in a single nest. If the nest is
disturbed, for example, by a person trying to destroy the nest, the queens will just move it.
The second fire ant here in Polk County is the Little Fire Ant. These are really small about 6 hundredths
of an inch long. Unlike the Imported Red Fire Ant all of the workers are the same size. They can also
have multiple queens in a single nest. Those nests are usually found under leaf debris, rotten limbs,
stones and the crotches of trees and clumps of grass. Often they are behind the leaf sheaths of palms.
Sometimes these ants will get into people’s homes and infest
clothing, beds, furniture or food. In homes they like to eat peanut
butter and other oily or fatty foods. Outside they will hunt small
animals, dead insects, and will tend honeydew-secreting insects
like aphids and scale.
Control of fire ants is difficult. For most home owners it means
finding nests and poisoning that nest. The following are 6
A detailed look at a fire ant
1.
different mound treatments:
Drenches: The drenches can range from pouring several gallons of boiling hot water into
the nest (this method is not recommended as it is easy to get burned by the boiling water)
3.
4.
5.
6.
to gallons of a recommended liquid pesticides
such as bifenthrin. The advantage of the
drench is that it is easy but the disadvantage is
that it is easy to miss the queen in which case
the nest will just rebuild itself.
2.
Surface dust: This method
applies a pesticide dust over the top of the
mound and then water is used to soak the
nest. Just as with a drench, the pesticide can
A single fire ant
miss the queen.
Mound injection: A liquid pesticide can be pressurized and injected deep into the mound.
This is more expensive and requires special equipment which might be beyond the reach of
most homeowners. It is a better method than a drench or surface dust but can still miss the
queen.
Baits: Baits are a food that ants will eat that is impregnated with pesticide. The bait is spread
around the mound not on it. The worker ants will then find the bait and when returning to
the nest with the bait will poison other ants including the queen. This method is slower
acting than then the other methods but more effective. It is the most common method
used around the home.
Mechanical control: There are some mechanical and electoral devices on the market that
are said to control fire ants. None of these methods have been shown scientifically to work.
Home remedies: Most of these home remedies are usually drenches, often boiling water or
a flammable liquid. These methods are dangerous to use because of the potential harm to
both the applicator, buildings in the area and the environment.
Red fire ants can be dangerous to people. Some people are sensitive to their sting; they can have an
allergic reaction that can cause them to end up in the hospital. Other people may not be so sensitive
but the sting is still painful. When you find a fire ant mound it is best to remove it from your property by
one of the methods described above. Pesticide baits designed for use on fire ants and labeled for that
can be purchased in most nurseries, big box stores, and other stores that sell pesticide.
More information on the Red Imported Fire Ant see the article:
http://edis.ifas.ufl.edu/pdffiles/IN/IN35200.pdf,
http://www.ars.usda.gov/is/AR/archive/sep99/ant0999.htm and
http://solutionsforyourlife.ufl.edu/hot_topics/lawn_and_garden/fire_ants.html
Information on the Little Fire ant can be found at: http://edis.ifas.ufl.edu/pdffiles/IN/IN29600.pdf and
http://www.ars.usda.gov/sp2UserFiles/Place/66151015/publications/Wetterer_and_Porter-2003(M3778).pdf