INTRODUCTION TO ANTS

Ants are one of the most successful groups of insects. They are social insects that live in colonies which are usually located in the ground, but they may enter buildings for shelter and/or food. Ants feed on practically every kind of food, but those entering homes are looking for sweets and/or protein-containing substances. Around 700 species of ants inhabit the United States and Canada. Of these, only about 25 species commonly infest homes.

Queens, which are typically the largest ants in a colony, function to establish new colonies and lay eggs. Once inseminated, they can lay fertile eggs for their lifetime which may be up to 30 years (harvester ant queens). For most species, a colony may contain many functional females or queens but only one founding queen. In the more common species, unmated females have wings and mated females remove them. The male is usually between the worker and the queen in size and his only function is to inseminate the queen. Reproductives are usually produced only in very large or old colonies. Males die shortly after mating, usually within 2 weeks. For a particular species, if the females are winged, the males are also winged and retain their wings until death.

New colonies are founded at different times of the year, depending on the species. The swarmers (winged reproductives) usually come out of the nest, mate, and the inseminated queens remove their wings and start a new colony in a suitable habitat. However, Pharaoh ant swarmers produce no external swarm and mate in the nest, with new colonies being established by budding. Argentine ant female swarmers do not swarm externally. Male Argentine ant swarmers sometimes do swarm externally, but mating still occurs in the nest and new colonies are established by budding. All colonies of a particular species tend to swarm at the same time in a given area.

Adult ants, workers and reproductives, do not eat solid food. Instead, they eat only liquids which may be stored in their crop. Workers may regurgitate a tiny droplet of liquid to a fellow ant when solicited by antennal palpitations or stroking. Larvae are fed predigested or regurgitated food. Older larvae may process solid food into liquid form.

HABITS

As with many other insects, moisture is the key factor that determines the suitability of a potential harborage site. Ants will exploit situations that have sufficient moisture, provide shelter, and have a nearby source of food. Moisture sources may be stones, wood, or other objects on the ground that physically retard moisture evaporation and/or act as a heat sink and cause condensation on their underneath side. Other sources include mulch and/or dense vegetation that traps moisture underneath it and/or retards drying air currents, in addition to the free water from downspouts, overflowing gutters, poor grade, leaking faucets, irrigation systems, etc. The food comes from honeydew-producing insects that feed on plants and the many insects that are themselves attracted to areas of high moisture. Such conducive conditions are most common in the landscaping around the foundations of structures.

CLEMENTS APPROACH TO CONTROL

1. Correct Identification: This is crucial to the selection of the appropriate control techniques. Species have different nesting preferences and habits. Most species are best controlled utilizing the application of non repellent pesticides. However, some species can best be controlled (or at least have the length of the control period extended) by utilizing pesticide baits, while others may require wood and/or void injections of pesticides.

2. Location of the Nest(s): Nest location is often crucial, or at least determining if the ants are coming from outside or under the structure. Ants tend to trail along/in corners or along/on edges such as the top of baseboards, the edges of countertops and splash boards, or under the edges of carpets, and they tend to use the tops of wires and pipes in walls as a highway system. Location of the nest can often be accomplished by following the trail of foraging workers back from the food source. Such workers will have their abdomens distended or swollen and/or they will be carrying bits of food in their mandibles. Outside, be sure to pull back the grass from around foundation walls and the edges of concrete sidewalks and driveways because ants will trail below the grass line where they cannot be seen; likewise check below the mulch line. Check under and/or in objects on the ground such as stones, boards, logs, firewood, landscape timbers, debris, etc., and tree trunks for tree-infesting species. After the nest(s) is located, direct pesticide application will usually eliminate it. Depending on the nest location, use aerosol, dust, or liquid formulations as is appropriate.

3. Exclusion: This involves sealing possible routes of entry such as any openings around pipe and utility line entrances, window and door frames, wall-mounted A/C units, light fixtures, fascia boards, etc.

4. Perimeter Treatment: Such  treatment  zones  are  usually  effective  in  reducing or preventing inside entry. This includes the application of an appropriately labeled non repellent pesticide. Be sure to treat under any siding-to-foundation wall junction. Treatment of infested trees may be required for tree-nesting species such as carpenter and velvety tree ants. For some species, the application of a highly-repellent pesticide may be desirable along the  property  perimeter  after  the  ants  have  been  eliminated  on the customer’s property, e.g., White Footed Ants. Mound drenches may control other species.

5. Interior Pesticide Application: The light application (misting or spritzing) of a non-repellent pesticide directly onto foraging trails of ants inside is often required. This will usually give results within several days.

6. Baiting: This is often the most effective way to control some ant species such as fire ants. With other species, it may prolong the control period if used outside along with non repellent pesticides (e.g., Argentine and odorous house ants). Baits are particularly effective when used very early in the spring when the ants first become active. At this time, the ants are very hungry and there are few sources of food available.

7. Other Non-Chemical Control Methods: Depending on the ant species involved, these may include one or more of the following: sanitation to remove ant food such as garbage, removal of plants attractive to ants (heavy nectar producers), changing landscaping to discourage ants, eliminating or keeping plants treated that are attractive to honeydew-producing insects such as aphids (plant lice), scale insects, and mealybugs, trimming tree and shrub branches to eliminate entrance via branches in contact with the structure, reducing moisture sources such as eliminating dense vegetation, keeping gutters clean, and eliminating sources of condensation, and replacing outside hollow-core doors with solid doors.