The first step in any pest management plan is to identify the pest. With ants this can be quite difficult because of their small size. A microscope with greater than 30x magnification is often needed to identify them. Most folks won’t have access to a microscope, so you can bring the specimen to your local county Extension office for identification. Some states, like Tennessee, have a distance diagnostics system which allows county agents to take microscope-assisted digital images and upload them to a web site where trained diagnosticians can identify it. Identifying the ant is important because ants have different food preferences and different behaviors that will directly impact the efficiency of an ant pest control program. For instance, some ants do not feed on oils, so baits with an oil carrier, but no protein and no sugar, are not fed upon by them. This is the case with the small, blackish Argentine ant and odorous house ant – two ant species often encountered in and around homes. There are over two dozen pest ant species in the U.S., but the species considered pests will vary from region to region. For example, the odorous house ant is found throughout much of the U.S., but the Argentine ant occur mostly in the southern and west coast states. For this reason, you should contact your local county Extension office for information specific to ants in your area. What follows is a general description of ant management practices and links for further information. Sanitation: Ants enter homes in search of food, water and favorable nesting sites. Meticulous housekeeping eliminates significant ant problems by removing needed resources. Furthermore, ant bait treatments are more effective if alternative food sources for the ants are eliminated as much as possible. Eliminate sources of moisture and food: Fix leaky faucets, remove standing water, etc. Replace wet or rotten wood. Clean window sills of dead insects that serve as food for ants. Remove the food source if ants are trailing to food. Use a mild detergent to wipe ant trails and remove the trail pheromone. Pest-Proofing — Removing access to nesting sites and conditions conducive to nesting and entry: Most ants prefer to nest in soil or wood outdoors, but homes offer many favorable nest sites for certain ants. Cracks and holes in brick veneer, wall voids and structural wood close to heat and moisture sources are commonly used. Locate the entry point into the structure, such as a hole in the foundation around plumbing or poorly-sealed windows and doors, and seal these areas to prevent future invasions. Check potted plants and firewood for ants before bringing them indoors. Keep branches, vines and other vegetation from coming in contact with your house because ants can use them as nest sites or to gain access to the home. Pull mulch, a common nest site, 12 -18 inches away from the foundation of the structure. See links at end of this answer for more information on pest-proofing. Monitoring, Inspection and Nest Location: Because many nests can occur in a single home or other structure, it is important to locate all nests or areas of foraging activity. Monitoring will find small, isolated colonies that otherwise might be overlooked and that could cause re-infestation in the future. Once all areas of foraging activity are located, they can be baited. If the nests can be located, they can be treated directly. Make a map of the house or structure. Place index cards containing honey or jelly on window sills, sinks and other possible food, water (drains, sinks, counter tops and toilets) and nest sites throughout the structure. In warm weather, placing monitoring index cards outdoors against the structure on window sills, around entrances and exits, water spigots, pipes, AC/heat units, attic vents, etc. may attract the most ants. After placing baits, wait at least 30-45 minutes and return to the monitoring cards. Follow the ants back to the nest, if possible. Cards may be left in place longer if you need to locate an outdoor nest, but be aware that the food may need replenishing or other ants may displace the ant of interest. If baits are to be used for control, place a bait station next to the monitoring card prior to disturbing the ants, and gently tap the ants onto the bait station. Although inspection, sanitation and exclusion practices take time and effort, they eliminate undirected, ineffective insecticide spraying indoors and make ant elimination by nest treatment quick and efficient. Baits: Effective bait formulations contain slow-acting pesticides that are collected by foraging worker ants and brought back to the colony, where the pesticide is fed to the other ants, queen(s) and brood. Baits exploit the forager caste, causing them to introduce the toxicant into a previously inaccessible nest. Because the toxicant works slowly, it is not associated with death in the colony and therefore is continually fed upon. Bait acceptance is of the utmost importance. If the ants will not feed on the bait, it is useless. Some ants are fickle, especially Pharaoh ants. They are reported to switch feeding preferences. Prior to placing bait stations, offer several different baits and see which is most attractive to the pest ant. Use information about sweet or grease preferences to select baits. Place bait stations where ants have been seen or were attracted to sweet food on the index cards as described in the previous section. For specific pesticide recommendations for baits used in and around homes in your state, we suggest that you contact your local Cooperative Extension Office Direct nest treatment: If nests are indoors and can be located, treat them with an insecticide registered for this use. Be careful. Many times we locate a foraging trail disappearing into the wall and not the nest. Dust formulations are preferred for treating nests found in indoor voids because they do not stain and generally give longer residual control than sprays. Apply dusts sparingly in thin, even layers in the ant nest area. Pest-control professionals have equipment to drill holes into colonies nesting in wood and wall voids and for injecting insecticides directly into the nests. Professionals also have access to many other dusts and residual liquids. If nests are located outdoors, see links below for information on individual mound treatments (baits, drenches, granules, dusts, aerosols or excavation), broadcast baiting and surface applications. Barrier treatments around the home: When ants invade from the outdoors, pest-proofing is a more permanent solution to prevent outdoor-nesting ants from entering the home. Pest-proofing can be supplemented with a chemical barrier if the physical exclusion methods are not as effective as needed. Applying fast-acting sprays to the exterior of the home may aggravate the indoor-nesting ants and cause them to be more visible to the homeowner because they may no longer forage outdoors. To add a supplemental chemical treatment to the home, spray the soil around the perimeter of the home and the lower part of the house. The distance to spray up the foundation and onto the soil will be specified on the label. Entry points can also be sprayed. Many pesticides are labeled for perimeter treatments. Pest management professionals have access to wettable powders and micro-encapsulated formulations which are persistent on porous surfaces, and newer chemistries that are unavailable to homeowners. Fipronil is an example of a newer chemistry that is currently unavailable to homeowners as a spray and has been very effective in research trials against odorous house ants when applied as a perimeter treatment in combination with an outdoor liquid baiting system. Granular insecticides can be used instead of sprays to treat the soil next to the foundation. Often the granules need to be watered to release the insecticide. Do not routinely treat the entire premises for ants. Ants are generally beneficial in our landscapes as they scavenge for food and prey on other potential pests such as various caterpillars and chinch bugs. Some ants collect and feed on weed seeds. For further information on ant management:

Tennessee

Managing Structure-Invading Ants (PB1629)

Updated pesticide recommendations for Tennessee

California How to Manage Pests Series, Ants

Texas House-Infesting Ants and Their Management (L-2061)

U.S.

S. Hedges. 1998. PCT Field Guide for the Management of Structure-Infesting Ants – 2nd Edition. Franzak and Foster, Cleveland, OH 304 pp.

For further information on pest-proofing:

Managing Pests Around the Home (PB 1303)

How to Pest-proof Your Home (EF 641)