Ant Control Techniques by Ralph H Maestre BCE

Ant control can and will be difficult to obtain. Ants still remain the number one pest on most pest management professional lists. Many methods are employed to control them and many fail. Long term methods generally employ exclusion or pest proofing. I will explain some of the current methods used by MPM. First I will give a very brief introduction of the different ant species we deal with and then speak on the control techniques.

Carpenter Ants· Small minor workers ¼ inch long · Large major workers ½ inch long · Large black or reddish ant · Polymorphic (multiple sizes in the colony)

One the most prominent species of ants we encounter is the carpenter ant. There are several species, but all are treated in the same way by us. Carpenter ants are among the largest ants found in homes and live in colonies containing three castes consisting of winged and wingless queens, winged males and different sized workers. Winged males are much smaller than winged queens.

Swarmers emerge from mature colonies usually from March to July. The colony does not produce swarmers until about three years later. A mature colony, after three to six years, has 2,000 to 4,000 individuals. Workers regurgitate food for nourishment of the developing larvae and queen.


In later generations, workers of various sizes are produced (polymorphism) into major and minor workers that are all sterile females. Nests are usually established in soft, moist (not wet), decayed wood or occasionally in an existing wood cavity or void area in a structure that is perfectly dry. The walls of the nest are smooth and clean (sandpapered appearance) with shredded sawdust-like wood fragments, like chewed up toothpicks (frass), carried from the nest and deposited outside.


The most important and often most difficult part of carpenter ant control is locating the nest or nests. Once the nest location is found, control is very easy and simple. Steps to a successful inspection include an interview with family members, inspection indoors, inspection outdoors and sound detection.

Pharaoh Ants· About 1/16 inch long · Light yellow to reddish brown with abdomen slightly darker · Monomorphic workers · Has two nodes and no spines on the thorax · No stringer · Three segment clubbed antennae

Female Pharaoh Ants can lay 400 or more eggs in her lifetime. Mature colonies contain several queens, winged males, sterile females or workers, eggs, larvae, prepupae and pupae growing to as large as 300,000 or more members.

Periodically a queen, together with a few workers carrying immatures (eggs, larvae and pupae), leaves the nest and sets up a new colony elsewhere, quickly spreading an infestation. This behavior pattern is known as "satelliting," "fractionating" or "budding" where part of the colony migrates to a new location rather than by single females dispersing after a reproductive swarm. Budding may occur due to overcrowding, seasonal changes in the building's central heating and cooling system or application of a repellent pesticide (really known as fission).

Nests usually occur in wall voids, under floors, behind baseboards, in trash containers, under stones, in cement or stone wall voids, in linens, light fixtures, etc.

Pharaoh ants are usually much harder to control than other ants because of their ability to disperse. About 90 percent of the colony remains hidden in the nest so even if 10 percent of the colony is killed by a residual pesticide, the remaining reservoir of ants is enormous. Conventional contact pesticide applications especially repellent products such as pyrethrins may spread infestations to new areas with multiple colonies blossoming within the structure. These ants will avoid certain pesticides.

Odorous House AntsBrown coloration Body 1/8 inch in length Workers are all one size (monomorphic)

Colonies vary in size and range from a few hundred to 10,000 individuals, usually with multiple queens. Sexual forms are produced only in colonies that are at least four to five years old. Mating may take place within the nest or nearby. Colonies multiply when one or more fertile females accompanied by numerous workers leave the parent colony, found a new nest, and start a new colony. Single inseminated queens from nuptial flights also may establish new colonies independently.

The odorous house ant, Tapinoma sessile (Say), is a native species that occurs throughout the United States. Outside, it commonly nests in soil beneath most any object, including stones, logs, concrete blocks, and fallen limbs. It also nests under the bark of logs and stumps and in plant cavities, refuse piles, under mulch in flower beds, and nests of birds and animals.

It is critical to survey inside and outside to locate all nests. Nests found outside can be drenched with a residual insecticide. When numerous ants appear around the building foundation, a perimeter treatment with a residual non-repellent insecticide should be used. Baits that have a protein or sugar-based attractant may be effective when the nest is not accessible.

Magic’s Management Program always begins with baiting. Use the various baits we have available like Intice gel, Intice granular, Advance gel, Advance 388B, Advance granular, Advion Pucks, and the new Advion gel. All of these are highly effective bait. Use the buffet style of baiting, this means don’t rely on only one of the baits. You will fail and numerous call-backs will occur. In conjunction with this you may use only a liquid spray, such as Phantom. Use Phantom both outside and inside the perimeter of the structure. This is a non-repellent and is effective. There are new products Fast-out foam and Transport GHP new to our arsenal. These products are showing very good results and are also non-repellents. NyGuard is an IGR that can and should be incorporated into our pest management program against ants. NyGuard may be used with both non-repellents and baits.

Termidor is to be used only by the field supervisors. This is a last resort situation.When it comes to carpenter ants, if the nest is located then we will drill and inject product using the actisol machine or dust. The dust may be Drione, Tri-Die, or Borid. Repair to leak can be handled by our carpentry division.

Nest found outside, small mounds of dirt, may be sprayed using pyrethroids. This is the only time you may use one of these products. Phantom cannot be used always from the structure. Always read your labels and provide them to the customer.

If a follow-up is needed, then it should be no less than ten to fourteen days later. This will allow for the product to take effect.

		Potentially two other species may be found in our area that enters structures. The first one is the False Honey Ant, Prenolepis impairs, the workers are monomorphic, 2 to 4 mm long, and have a one-segmented petiole. Also known as the small or winter ant is found throughout the US and often associated with Oak trees (Gregg 1963; Ebeling 1975; Wheeler and Wheeler 1986). They like damp soil in shady places and are usually the first ants seen in the spring time. Treatment consists of gels or baits with dust being used in void. Direct liquid treatment to nest site is recommended.
	The other potential pest ant is the Black Garden Ant, Lasius species, has workers approximately 2-5 mm in length and is monomorphic. They have several different species with various body colors. Black Garden Ants are found throughout the US. This ant forms mega-colonies with multiple queens. They tend aphids for honeydew and eat living and dead insects. They love sugar-based products inside home. The colony size may reach over 100,000 ants and cover very large areas. One colony in Europe covered northern Spain, southern France into northern Italy. That is like saying one colony covering an area from New York City down to Washington DC. This may be an exaggeration but you get the idea. Anything you do on a property may only be like trimming your finger nails. The colony will bounce back very quickly. A very aggressive approach would be needed and only a service manager with the technician can ascertain what the proper approach would be.