As red imported fireants spread into more populated areas of the state, more people
are likely to be stung. Encounters with fireants can be expected not only outdoors,
but indoors as well. Forging ants have invaded homes as well as buildings such as
offices, hospitals, and nursing homes.
In these situations, fireant control is potentionally more difficult because of
concerns related to both the ants and the indoor use of chemical insecticides.
Because fireants cannot be eradicated over wide areas, the goal should be to manage
the ants with a combination of chemical and non-chemical control tactics.
You want to elliminate fireants in the areas where the pose the most immediate
hazard to people and animals. Fireants spend a great deal of time searching for
food. That forging activity can bring them inside buildings. You can reduce ant
forging around buildings by eliminating available food sources.
Outdoor trashcans around schools, parks and other buildings should be emptied
frequently during the day. Avoid leaving trash in them over night. Keep the area
around trash cans clean. At home trash cans should have lids on them. Dumpsters
and grease bins found in at food service facilities should be emptied routinely, and
the areas around them kept as clean as possible.
Keep shrubs pruned away from buildings so that ants can't use them as a bridge to
avoid treated areas.
There are 2 basic approaches to chemical controlled fireants. An insecticide could
be applied to individual mounds or it my be broadcast over a wide area infested
with fireants colonies. Individual mound treatments are usually more
environmentally acceptable because they use less insecticide and limit the areas
treated. They are also likely to have less impact on non-target insects. Regardless of
the method used, the objective is to kill not only the worker, but also the queen
because she is the only ant in the colony capable of laying eggs.
Because insecticides are toxicants it goes without saying that fireant chemicals
should be used according to label directions. There are several different insecticides
formulations for controlling fireants that you can purchase at your local farm and
garden center. There are baits, drenches, powers, and granulars to choose from.
The formulation that you choose will depend on how extensive the fireant
infestations is on your property. Each insecticide formulation is applied in a
different way. Fireant baits are granular formulations that contain slow acting
insecticides dissolved in soybean oil. The oil is a highly attractive food source for
fireants. Consequently, ants that are forging for food readily pick up and carry bait
particles back to there nests where the oil is abstracted from the particle and fed to
the queen and immature ants.
A fertilizer or seed spreader can be used to broadcast baits over areas of the
landscape that are infested with fireants. Because ants are forging for food away
from there mounds you do not need to apply bait to every area of your yard. But it
is important to uniformly apply the bait at the rate specified on the product label.
The manufacturer should have provided instructions on how you can calibrate your
application device. A broadcast treatment is the best control option when the
infested area is large, and infested with too many fireant mounds to treat
individually. Once they discover the bait, ants will carry the bait product back to
the mound and distribute the toxicant to the whole colony. Then it was just a matter
of time before the ants are killed and the mound is destroyed.
In addition to broadcast treatment, baits can be applied to each mound. Mound
applications is best used when they are just a few ant mounds to control. Use a
measuring spoon to sprinkle the bait around each mound according to the label
directions. Baits should not be applied to the top of the mounds since fireants don't
forge for food in this area. Baits should be applied when ants are actively forging
that is when temperatures are above 70 degrees and below 85 degrees fahrenheit .
Some insecticides are mixed with water and applied directly to the mounds.
granular insecticides can be applied to the surface of the mound, and then water is
applied to leach the insecticide down into the mound. It takes a minimum of 2
gallons of water per mound to distribute the insecticide deep enough to contact all
the ants in the mound including the queen. That's a lot of water hauling unless there
is just a few mounds to be treated.
The drenched method works best if you don't disturb the mound. Be sure to follow
the directions carefully when preparing to drench. Just pour the drench over the
surface of the mound slowly enough that it runs down into the mound. Also, be sure
to pour some drench around the edge of the mound.
Powers are another type of individual mound treatment. The toxic power works its
way down into the mound exposing immatures and the queen to the insecticide. For
high risk areas, where it is likely that people and pets maybe attached by fireants.
A preventive treatment may be the best choice. There are products on the market
that can be applied to high traffic areas to control fireants , and keep them from
moving in for up to one year. These products can be applied as a granular just like a
fertilizer. They must be watered in before they become effected. They are the most
expensive of the fireant control products available. But for high risk areas, they
may be worth the money.
To eliminate just a few fireant mounds , anyone of the fireant formulations just
described will work. However, if your property is infested with a large number of
fireants colonies you should consider using a combination of methods.
First, broadcast fireant baits over the entire infested area, use a seed or fertilizer
spreader to obtain uniform coverage. Next, several days to a week after the
broadcast treatment , treat individual problem mounds . Only treat does mounds in
high traffic areas . The two step method of fireant control can be applied at
anytime. But it's most effected when applied in the spring and in the fall.
There are some non chemicals methods available that can be used against fireants .
They my be limited in there effectiveness., however. Water heated 90 degrees
fahrenheit or hotter and mechanical disruption have been used in many instances.
Evaluations done at Texas A & M University have shown that these treatments will
kill large numbers of ants. However, satellite mounds, formed by surviving ants
subsequently appear. Thus these methods have a useful, but temporary impact on
fireant colonies. They may be necessary to use in situations where pesticides of any
type are considered unacceptable.
Other non chemical mechanical devises that disrupt colonies do not have
scientifically based test data to support there effectiveness. One potential down side
to using hot water is that it can damage or kill vegetation in the general vicinity.
The key to reducing the threat of fireant infestation indoors is prevention. Which
menas removing exposed food sources that may attractive these insects. In some
cases, fireants my nest indoors inside walls or under concrete slab floors . In these
instances, you will likely see soil and other debris pushed out around expansion
joints near the edge of carpeting, or around water or other utility pipes. In those
situations , fireants are simply entering the building from an outdoor nest. The
treatment objective must be to reduce the potential for accidental stings as quickly
as possible.
Insecticides labeled for indoor use can be found in the NC Agricultural Chemicals
manual. The pyrethroid insecticides products containing chemicals such as
permethrin, cyfluthrin, or Bifenthrin can be used in home and public buildings to
drive out forging ants. Select products that are specifically labeled for indoor use.
Be sure to carefully follow directions that come with the pesticide you choose.
Although baits work will for many ants species, they are not the best choice for
controlling fireants indoors. Because they are likely to draw more ants inside. For
this reason, it is important to positively indentify the ants that are invading your
home before applying any control measures.
Information about other ant species, can be found in A Guide to House-invading ants
and their control.
For information on controlling fireants in your area, contact your local office of NC
Cooperative Extension.