Pest management requires a systemic approach when dealing with ants. Our professional technicians must draw on his or her knowledge of each specific species, their habits and their biology, in order to determine the most effective strategy for controlling the infestation.
Proper identification will help the professional find nests, entry points, and other infestation signs. For example, pavement ants build nests in soil, while carpenter ants nest just outside trees or stumps. Worker ants gain entry to buildings through cracks in a slab or expansion joints. In addition, the conditions leading to the infestation should be examined. Our professional technicians talk with the client who can provide essential information.
Long term effectiveness of infestation control requires the professional to teach the client about the factors surrounding infestation. Key points about ant biology and behavior such as poor sanitation, moisture from poor ventilation, clogged gutters or leaky pipes, or earth to wood contact, and stacked wood and debris surrounding a structure should be mentioned. Even ornamental plants infested with homopteran insects can attract ants.
These environmental factors must be corrected for there to be long term control of infestations. After the extent of infestation is measured and the species, nests and entry points are identified, there are three possible strategies. First, modify habitat or environment so the colony cannot survive. This could include, for example, repairing a leaky pipe, or removing a source of water that is attracting the ants. Second, mechanical methods such as trimming shrubs, removing vegetation and caulking entry points can be used to remove access to buildings. Third, the professional can use chemical treatments such as dusting the void, using bait, or drenching the mound.
Residual insecticides should be applied directly to the nest for the best results. The formulation choice and application are determined by the type of nest site. Ants nesting in voids within a structure can be treated with dust, aerosol, or foam. Accessing the void can be done through drilling a hole, or using a pre-existing point of entry. A bulb duster is sufficient for a local infestation, but for something more extensive, the professional can use a large hand duster. Dust should be applied in a light, thin layer so it doesn’t become repellent to ants. Insulated voids are treated best with a residual aerosol. A satellite nest of carpenter ants located under attic insulation can be removed by vacuuming and applying a local residual insecticide to handle any ants that visit from the main colony. Foaming is another good option. Foam is a shaving cream consistency that expands to reach into difficult spaces. It fills the void and coats the surface with insecticide.
Ants nesting in wood such as structural timber, fence posts, or landscape logs can be treated by drilling into the wood and injecting aerosol, dust, or a water based product. These can also be applied to nests located in stumps and tree holes. Ants nesting in soil such as lawns, landscape beds or under yard objects like stones or landscape logging can be drenched with water based insecticides. For large colonies like those made by field ants or red imported fire ants, a gallon or more of insecticide might be necessary.
Landscape such as pine straw, mulch chips, and/or dead leaves might reduce the effectiveness of insecticides because of the quantity needed to penetrate the mulch. Applying water based insecticides in mulch is rarely effective, so the mulch should be raked back before application. Afterwards, the surface can be treated as well after the mulch is moved back in place.
Ants nesting in wall voids, attics, crawlspaces, and/or ceilings between floors due to possible cold weather on the exterior and under slab foundations are hard to control because of their inaccessibility. Here, baits are the preferred treatment. If ants are not attracted to the bait, the slab can be drilled under in order to treat soil, and a termiticide labeled for treating under slab foundations can be applied. Since the place where ants emerge from under the slab may not be the real location of the nest, a number of holes might be necessary. Application of the termiticide as a foam may be helpful, and cracks in the slab can be sealed to prevent alates from entering spaces above the slab. Finally, ants nesting under stacks of material such as lumber or bricks usually require unstacking the materials so that the exposed colonies in the area can be treated using a water based formula.
Applying treatments around the perimeter of the building using a residual formula or a granular formula can be effective in treating ant infestations. Single active ingredient formulas like fipronil, many pyrethroids, and thiamethoxam can be used for perimeter treatments, as well as combination active ingredient products like bifenthrin and beta-cyfluthrin.
Barriers have different degrees of efficiency depending on repellency and contact activity. Some pyrethroid products, for example, are highly repellent to ants and may cause an increase in activity if indoor ants are cut off from the outdoor colonies. Trapped ants may be more visible to the buildings occupants as they search for an escape route. Synthetic pyrethroids, on the other side, are not repellent to ants, but are toxic and suppress recruitment, thereby controlling ants. Treating perimeters with a slower acting, non repellent insecticide like fipronil causes ants to pick up the insecticide and take it back to the nest. Fipronil’s success is thought to be because of horizontal transfer, especially that caused by necrophoresis or movement of dead ants infected with it. Creating truly effective barriers is difficult because gaps of any size are potential gateways. Other additional factors reduce barrier effectiveness. These include chemical degradation, dense ground cover and mulches, direct sunlight or other high temperatures, irrigation, and substrate alkalinity.
Insecticide baits are formulated as liquids, granules and discrete solids. Liquid bait is often an ideal compound for ants that have become hybridized with honeydew-producing insects. For example, Argentine ants will consume more sucrose when it is applied in a liquid, instead of a gel. Maximizing the consumption of granular-type baits is best accomplished by determining the particle-size preference of each individual ant species. The most effective bait formulas have several characteristics, as a bait must both attract the ants and be palatable so it will be readily consumed by forager ants and then brought back and shared with the other ants in the colony. Other substances added to ant baits, like emulsifiers, need to be palatable as well. Toxicants must have a delayed-activity component, in order to allow the bait to be fully distributed throughout the colony.
Insect-growth regulators, known as IGRs, and metabolic inhibitors are two commonly-used toxicants in ant baits. IGRs are designed to work slowly, to interfere with reproduction. Conversely, as compared to IGRs, metabolic inhibitors tend to work quite rapidly through interfering with cellular respiration. Laboratory test suggest IGRs may be especially suitable for controlling ants that have multiple nests. Additionally, new active ingredients in gel baits, like fipronil, give pest-control professionals more options for successful baiting.
The selection of baits typically depends on the food preference of the ant species. Proper sanitation of the bait area is also crucial, so that other sources of food are not competing with the bait. Our professional technician can use multiple bait approaches during the treatment to gain control of the ant population. The ants should be given about a week to feed on the toxic baits prior to initiating any follow-up attempts. Careful handling of the ant baits is necessary following use of other products to prevent contamination of the baits.