The Great Ant

Ants are the No. 1 pest of homes in most areas of the United States, particularly in the southern and western states. In some states, ants are also the No. 1 pest in commercial buildings. Pest control operators rank several types of ants, such as fire, carpenter, crazy, Argentine, and pharaoh ants, as their toughest tests in controlling pest infestations. instructed to place a Post-It note along each trail of ants they see during the evening. This will make it easier to determine exactly where the customer is seeing ants when the follow-up service is performed.

• Don't place baits on treated surfaces. It is obvious that ants are extremely unlikely to forage on surfaces treated with residual insecticides, and that if they do so

The use of baits is fast becoming a staple of the pest control professional's array of strategies for controlling infestations of ants in and around buildings. Manufacturers are working feverishly to bring new baits to the marketplace to control many different species of ants.

The pest management professional's options with ant baits are more numerous than they have ever been. Yet many fail- ures occur in attempting to eliminate ant infestations with baits. What happens in these situations to cause failures that lead to customer dissatisfaction and reduced confidence in their pest management company? This article will examine some of the factors that affect the success and failure of bait strategies for ant control.

PRIMARY STRATEGY. To eliminate a particular ant infestation, all ant colonies in and around the building must be found and killed. It has been reported by researchers in a 1913 USDA publication that only 1% of an Argentine ant colony can sustain the remainder of the colony and eventually re-establish it. This research would likely hold true for many species of ants that have multiple queen colonies, and this factor demonstrates the need for an effective, planned strategy that is thorough and complete.

The primary strategy for most ant species is to find and treat the colonies directly with an appropriately labeled insecticide. By exposing the colony and treating it directly, it is likely that all members of the colony will be eliminated. For ants with satellite colonies which includes many of the structure-infesting species thoroughness is a key. The only ant for which the find-and-treat strategy has no merit is the pharaoh ant, because of its cryptic nesting habits. Baiting is the only effective control strategy for this ant.

Baiting should never be the first option for most ant infestations, except for the pharaoh ant. Quicker results may almost always be achieved through thorough inspection and carefully directed treatments. In some cases, however, the ant colony cannot be found; or the ant colony is not easily accessible (e.g., under a slab floor); or the ants are located in a sensitive area (e.g., a hospital intensive care unit). Baiting is definitely the primary option in these situations as well as for all situations involving pharaoh ants.

IT'S UP TO THE ANT. One of the key factors that is often overlooked when placing baits for ants is that the success of the baiting program depends on the type of ant you're dealing with. If the ants will not feed on the bait, the bait will not end up in the colony's food cycle. If the ants feed on the bait only intermittently or for a short period of time, enough bait to kill the colony will not be introduced into the colony's food cycle. These factors require attention and follow-up to overcome.

• Make sure the ants feed on the bait. The biggest mistake made with ant baits is to place them and then forget about them until the next scheduled service visit. At the very least, ant baits should be checked within one week; the best follow-up period, however, is the next day.

Are the ants finding the bait? If not, the bait needs to be moved into the path of active foraging trails. Customers can be of great help here because they are generally around when the ants are usually most activethe early morning, the evening, and at night. Ask the customer to point out exactly where trails are located. Be sure to look for new trails and to locate a bait placement along each newly identified trail.

Examine bait placements for ant activity. Has there been noticeable ant feeding on the bait? Are live ants currently feeding on the bait? Are dead ants present around the bait placement? (This may be observed during later follow-up visits.) If ants are not feeding on the bait, switch to a different bait and follow up again the next day. If the ants are still ignoring the bait, try a third bait if a third bait is available. To save time, many pest management professionals will place two different types of baits along active ant trails and check to see which one the ants prefer.

Just because a particular ant species (e.g., pavement ants) infesting several different houses prefers a particular brand of ant bait does not mean that all colonies of this ant will feed on the same bait. It is not uncommon to find that an ant species prefers Maxforce Ant Bait at one house, but the same species in another house prefers Pro-Control Dual Ant Baits. This factor can even occur within the same house when two different colonies of the same species are present, and also when two different trails from the same colony are involved.

The first step in a successful ant baiting program is to follow up to ensure that the ants feed on the bait. If not, switch baits, and if more trails are found, place additional baits. Baits cannot work if they are not introduced into the colony's food cycle.

• Place baits as closely as possible to the ant colony. Ants are like other animals in that they usually do not want to travel too far from their nest or harborage in search of food. If an acceptable food source is available close to the colony's location, that food source is likely to be more heavily exploited. When possible, place ant baits near where the trail is exiting a wall or crack in a slab.

• Place baits along edges and corners. Ants are creatures of habit. Like cockroaches, they like to crawl along "structural guidelines" formed by the edges of cabinets, the edges of walls, cracks in concrete, the edges of landscape timbers, the edges of tack strips under carpet, along wires and plumbing pipes, and so on. If a bait is placed away from such structural guidelines, it will be more difficult for ants to find it. The only situation for which you would not place a bait along an edge or corner is when the ant trail is exiting a hole in the wall or the trail is meandering across a wall in a closet or other secluded location.

• Don't forget electric outlet boxes. When dealing with pharaoh ants, electric outlet boxes and light switch boxes need to have baits placed inside them because pharaoh ants most often use electric wires to move through buildings. Why else would pharaoh ants be observed by customers trailing out from behind electric outlets and light switches? In fact, pharaoh ants are more likely to encounter and feed on baits placed inside these boxes than baits placed in more exposed areas.

Bait stations do not fit inside electric outlet and switch boxes, so one of the only baits that currently can be used is Drax Ant Bait. Drax should be applied only inside short pieces of plastic straws so that they can be retrieved and replaced when necessary. Place both types of Drax Ant Bait the sugar-based bait and the protein-based bait in each outlet box until it is determined which bait the ants prefer. Bait the outlet boxes in the kitchen, bathrooms, and any other infested rooms. Baiting outlet boxes can be time-consuming, but the results are well worth it.

• Remove other food sources. Given a myriad of food choices, ants are likely to continue to feed on foods they have been feeding on and ignore baits. The customer must be educated on the importance of cleaning up food particles, grease deposits, etc., as much as possible. Removal of other potential food sources will generally force ants to become more interested in feeding on the bait placement.

• Don't skimp on bait placements. Another important mistake made in using baits for ants is to limit bait placements to two, three or four placements. This is especially true when baiting for pharaoh ants. Each active trail needs to be baited because that trail could be from a separate colony. It is not uncommon for several small to medium-sized pharaoh ant colonies to be present in an infested room, especially if residual treatments have been made in the past in attempting to control the infestation. Remember, follow-up inspections are just as important for identifying new ant trails as they are for checking on ant feeding activity.

One tip for getting help in identifying pharaoh ant trails is to provide the customer with a pad of small, brightly colored Post-It notes. The customer should be instructed to place a Post-It note along each trail of ants they see during the evening. This will make it easier to determine exactly where the customer is seeing ants when the follow-up service is performed.

• Don't place baits on treated surfaces. It is obvious that ants are extremely unlikely to forage on surfaces treated with residual insecticides, and that if they do so they will die soon thereafter. Baits placed on such surfaces or baits that are subsequently "treated over" will be useless.

• Outside bait placements are a must. Pharaoh ants do forage outdoors during warm weather. In fact, the author has observed more foraging outside than inside in many pharaoh ant infestations. How often have buildings suddenly experienced pharaoh ant infestations inside in the fall after the weather begins to cool? It is likely that pharaoh ant colonies have been foraging outside and are forced by cold weather to begin foraging inside.

When dealing with pharaoh ants, inspect outside for trails and place at least one bait along each trail. In severe infestations, an evening inspection will result in more trails being identified and more baits being placed. If outdoor baiting is ignored, the elimination of indoor activity will take longer to achieve. Also, what seems like a reinfestation months later may simply be colonies situated in outside walls relocating to the interior.

• Some ants just don't feed on baits. Certain ant species are difficult, if not impossible, to control with baits. Crazy ants, ghost ants, carpenter ants, Argentine ants, and acrobat ants historically have been difficult to eliminate using baits. In the past two years, Maxforce Granular Ant Bait has been introduced and has demonstrated some success in controlling carpenter ants, but this success is not always complete. It is still best to search for and treat carpenter ant colonies directly, and then to use the Maxforce Granular Bait for preventing new infestations or for help in situations where the colony cannot be found.

Crazy ants will not feed on any commercially available bait long enough to effect a significant impact on the colony. This is also true with Argentine ants, although Argentine ants are more likely to feed on baits than crazy ants are. Both of these ants develop huge colonies with hundreds of queens, and the colonies are augmented by satellite colonies. In addition, Argentine ants fuse colonies to create "supercolonies" and will often split off colonies from the supercolony.

This constant movement and exchange of workers, brood, and queens between colonies is highly beneficial to Argentine ant colony survival. It also is the major reason that Argentine ants can be difficult to control. Inspection and direct treatment of all colonies in or on the property is the best strategy for both Argentine and crazy ants, although baits may be helpful in some situations involving Argentine ants.

Ghost ants, like pharaoh ants, have cryptic nesting habits with numerous small colonies often existing within an infested building. A number of pest management professionals have reported success in baiting for this ant, but this success is not close to 100% of all situations. Finding and directly treating colonies is still the best control strategy for ghost ants.

Acrobat ants will feed on some commercially available baits, but they never seem to feed enough to eliminate the colony. Find-and-treat is the best control strategy for acrobat ants.

CONCLUSION. The use of ant baits can be beneficial if employed properly and if follow-up evaluations are made. Total reliance on baits, however, is not a good approach, except for pharaoh ants. Quicker and more complete results are achieved by combining a find-and-treat strategy with baits. Persistence, thoroughness, and follow-up are the keys to success.