Pest control for ants has become a major topic for professional pest control operators and individuals who are interested in do-it-yourself pest control. The list of home remedies, over the counter sprays and products developed within the professional pest control industry is one that grows every year.
Of all the different pest control products for ants there are two basic groups of such materials: ant baits and contact insecticides for ants.

Contact Insecticides

The most confusing group (for the average person) is that which contains contact insecticides. Within this group are granules, sprays, aerosols and dusts.
A contact insecticide is basically exactly what the term implies: the ant (or other targeted pest) must come into contact with the material before it is affected by the material. There are hundreds of over the counter aerosols or sprays that can be used to spray directly on visible ants or ant trails. These products give immediate results (killing the ants on contact) but rarely solve the problem of ridding the home or building of ant infestations.

Ant Control Granules Granule Summary

Although there are granular ant baits, this section is an explanation of granular, contact insecticides. Some examples of granular insecticides are Diazinon, Dursban, Talstar, Over'n Out, DeltaGard. All of these products are used outdoors only and are not to be used inside buildings. In order for a granular product to work to its highest potential it should be broadcast over entire area of infestation. Many people will purchase granular insecticides and use them to spot-treat individual ant beds. Best results are achieved when the granules are broadcast over entire area where ants are known to forage for food or where ants are seen. Once the granules have been spread out over the targeted areas, water should be applied in order for the insecticide to work.
An insecticide granule consists of two basic elements: an insecticide (active ingredient) and a carrier or solid particle on which the active ingredient is impregnated. Older types of insecticides (Dursban, Diazinon, Oftanol) contain organophosphate materials. The newer types (Talstar, Over'n Out, DeltaGard) contain synthetic or man-made pyrethrin materials. Talstar contains Bifenthrin, Over'n Out contains Fipronil and DeltaGard contains Deltamethrin. These newer chemicals are safer for people, pets, wildlife and the environment than the older and heavier organophosphate insecticides.
If the granules are not watered or irrigated, the insecticide material merely sits on the surface. Ants that contact this particle will be affected but the ants that walk between particles (insects can easily be repelled by sensing your insecticide!) will rarely be affected or killed. By watering in the granules after application you will release the active ingredients into the soil, where the product is needed for ant control.
Another draw-back to not watering your insecticide ant granules is the effect of the sun. Modern products that contain Bifenthrin, Fipronil or Deltamethrin are more stable than older products once exposed to sunlight but they all need to be irrigated before the sun has a chance to degrade the insecticides. When granules are broadcast and have to wait for the next rainfall, the insecticide contained in the granules quickly begin to break down due to exposure to the sun's rays. In other words, water your granular product immediately after application if you want to get the best results for the money spent on the product.

Insecticide Granule Summary

Broadcasting entire area is more effective for ant control than dumping piles of granules on individual ant mounds.
Do not wait for the rain! Water or irrigate area immediately after application of insecticide granules.
Keep people and pets off of all treated surfaces until dry.

Ant Sprays

For the sake of this discussion, only liquid insecticides that are not in aerosol forms are listed as ant sprays. Aerosols will be mentioned in the aerosol ant spray section of the article.
When choosing an ant spray it is always better to purchase a concentrate instead of a ready mixed, ready to use (RTU) type of insecticide. Once an insecticide concentrate has been mixed with water, it should be used the same day; for best results it should be used within a couple of hours after mixing. The reason for this is simple: water is not friendly to insecticides. If you mix your insecticide concentrate with water and allow the solution to sit in your sprayer for a few days, the insecticide will not be as strong as when it was first mixed. You can easily lose 25 to 50 percent of the product's effectiveness within 24 to 48 hours. Water is an efficient and necessary tool for delivering pesticides to their targeted areas but (when not used in a timely manner) water also destroys your insecticide. For these reasons it is obvious that a ready mixed product will not be nearly as effective as a solution that you create by mixing concentrate with water. Indoor products should be specifically labeled for indoor use, which helps insure that the pesticide is safe to use in the environment where it is to be sprayed. Indoor ant sprays should be water-safe for fabrics and flooring and safe for humans and pets when applied as directed. Outdoor ant sprays are usually formulated so that the active ingredients and solvents contained in the pesticide concentrate will safely do the job stated by the label without burning or harming turf grass, shrubs, ornamentals and most ground covers where ants might be a problem.

Indoors, an ant spray should be applied to areas where ant trails have been seen or where ants are suspected of foraging for food or traveling from their food sources to their hidden nests. Safety first: treat areas where ants are most likely to come into contact with the material but where people and pets have the least contact. When it is necessary to spray floors or baseboards, make sure that children and pets are not in the area during treatment. Once the treated areas have been allowed to dry, children and pets can return to the areas.
Most of the ants that contact the surfaces you have treated will die within a very short time period. A good, professional ant spray insecticide should give you at least 30 days residual or insecticide activity. Standard liquid insecticides (usually denoted by the "EC" in their name) will last about one month on indoor surfaces. Microencapsulated products will last at least twice as long as an emulsifiable concentrate (EC) when used as directed. A wettable powder (WP) will last at least three times as long as an EC. Wettable powders cost a little more than liquid concentrates but can last as long as three to six months, requiring you to spray less often.
Spraying for ants indoors does not require the same volume of product as does treating the home for fleas or ticks. Flea and tick pest control requires that all flooring, carpets, rugs and most furniture be broadcast with product. When treating for ants you only need to spray areas where ants hide, forage for food or where they might hide. Suggested areas in a home include spaces between walls and plumbing lines, beneath false bottoms of cabinets, baseboards, underneath and behind major appliances such as stoves, refrigerators and freezers. Your insecticide label will list areas that the manufacturer suggests for controlling certain pests such as ants. When treating indoors and outdoors you need to inspect for and treat all possible entry points, hiding places and paths of travel of your household pests such as ants. Avoid poor and unsafe practices such as "hosing down" your countertops or other food prep areas with an ant spray. If this has happened in your home, thoroughly clean such surfaces with soap and water. In pest control, a little common sense goes a long way!

Outdoor pest control for ants is broken down into two sections: spraying the exterior surfaces of the home or building and broadcasting areas around the building.
Spraying the exterior of the home is simple but very important. Every possible entry point is to be sprayed. Pay close attention to any tiny space (as small as a pencil point, as narrow as the thickness of a business card) where ants or other bugs might enter a home. A pump type garden sprayer is best for this job, which is the same sprayer you will use for spraying indoors for ants.

Broadcasting the areas around a home or building will help insure that ant beds (both visible, above ground and not so visible shallow mounds under mulch, etc.) are contacted with your spray. The best sprayer for this job is a hose-end sprayer. There are several such sprayers on the market but you need to make sure that the sprayer you purchase for insecticide applications is manufactured with a siphon tube that will draw the insecticide solution from the sprayer, mixing as it sprays. Either a Gilmour Dial-A-Mix sprayer or a 20 gallon hose end sprayer will do a good job.
Keep pets and children out of area during treatment. Keep them off of all treated areas until dry.
The best concentrated products to use for your exterior broadcast ant spray are Talstar Concentrate or a professional Cypermethrin product such as Cynoff EC or Demon EC. Very little product is needed for each application, making these products safer and more economical to use.

There are hundreds of ant spray products that are available for purchase and use in and around your home. There are certain active ingredients that are safer than others (when used as directed) and that do a great job with no smelly residue. Cypermethrin, Bifenthrin, Permethrin and Deltamethrin are active ingredients that are used by professionals for the control of ants, roaches, spiders and many other household pests. The most popular concentrates used for ant pest control are Suspend SC, Demon EC, Cynoff EC, Demon WP, Cynoff WP. All of these products are either odorless or super low odor and are labeled for use indoors and all of these products are good ant sprays.

Ant Spray Aerosols

Professional aerosols are not usually used in the same manner as over the counter sprays purchased in grocery stores or home improvement stores. If a professional aerosol contains a residual insecticide, it should not be used to broadcast wide surfaces such as food storage cabinets or countertops. These aerosols should be used for cracks and crevices, only. A crack and crevice aerosol can be sprayed into hidden areas where ants are likely to be or known to be but where people and pets do not come into contact with treated surfaces. CB Invader and CB AirDevil are good examples of contact insecticide aerosols that are used to kill ants and other household pests.
When cracks and crevices need to be treated for ants, aerosols or dusts can be used. Insecticide dusts give better coverage (in places where ants hide or nest) than aerosol sprays.

Insecticide Dusts for Ant Pest Control

When a home is constantly being invaded by ants or when there is a severe infestation that cannot be controlled by conventional ant sprays, insecticide dusts can be a great tool for help in eliminating the problem.
Insecticide dusts should always be used in cracks and crevices, only. Do not broadcast dusts in open areas to control ants. Ants often enter a structure through plumbing and electrical lines. They also use these same routes to travel throughout the home in their search for food or as they scout an area for a suitable nesting site. Two insecticide dusts that work for ant control are Delta Dust and Drione Dust. Plumbing lines and areas around doors and windows (in wall voids) and the inside of hollow block construction normally have slight to moderate moisture levels. Plumbing lines will often have condensation. These moist conditions are detrimental to insecticide dusts. The exception to this rule is Delta Dust. This is a water-proof dust that contains Deltamethrin (the same active ingredient contained in Suspend SC.) Delta Dust is the perfect crack and crevice product for the control of ants in areas where sprays cannot be used effectively.
Many dusts are packaged and shipped in soft containers that can be used to dispense the material into appropriate areas. Best results are achieved when a hand bellows duster is used to apply your dust. A good bellows duster is the Crusader Duster. This is a small, hand held device that gives you the ability to safely and easily deliver your insecticide dust behind light switch covers and electrical outlets, between walls and cabinets, walls and baseboards or other such cracks, crevices, hiding places and entry points used by ants and other bugs.

Ant Baits

There are four different types of baits used in ant pest control: solid, granular, liquid and gel. Most types are self explanatory but first we must clear up a misconception: there is a big difference between an insecticide granule and a granular ant bait. While granular insecticides are used for outdoor ant and insect control and must be watered after application, ant baits are used outdoors and selected areas indoors but are not designed to be watered or irrigated. Insecticide granules are used as a contact insecticide; ant baits are designed to be picked up by the foraging worker ants and carried back to their colony.

The attractant and active ingredients contained in an ant bait are transferred from the worker ants to the larvae in the ant colony. From there the materials are shared with or transferred throughout the entire colony.
Adult ants cannot digest solid foods. Solid foods are fed to ant larvae who can digest solids. The materials are then passed on to the rest of the ant colony as liquids that are regurgitated by the larvae.
If you will watch an active ant trail, you will notice that there is a line leading to the food source and another line returning to the colony. Solid food particles can be seen in the jaws of the workers as they transport the foods back to the ant bed. Many times you will notice that the workers returning to the nest are not carrying solids but their bellies seem to be swollen. This is because they are transporting food in liquid form.
Granular baits can be broadcast around the exterior of buildings and in other areas where ants are seen as they look for food. These granular products can be used indoors if placed in attics, crawl spaces, wall voids or other areas that are not accessible to children and pets. Maxforce Granular Insect Bait, Advanced Carpenter Ant Bait, Niban are all examples of professional granular ant baits.
Solid bait stations can be used indoors and outdoors but are best suited for indoor use. Simply place the stations in areas where ants normally trail or forage for food. Most professional ant bait stations have a see-through top for easy inspection. When ants eat all of the bait in any station, replace it with a new one. Fluorguard, Maxforce and Dual Choice are good ant bait stations to use.
Gel formulations are also effective for the control of ants and offer a wider range of places where the bait can be placed. Ant bait gels are normally packaged in a type of syringe that allows you to put out small spots of bait or inject the bait into cracks, crevices or entry points where the ants can locate the bait while foraging. A very popular device made for such baits is the Ant Cafe. With an Ant Cafe you can make your own, reusable bait stations. Gourmet Ant Bait Gel and Maxforce Ant Killer Bait Gel are the best baits in gel formulation.
Liquid baits such as Gourmet Liquid Ant Bait are becoming popular in situations where ants such as Argentine Ants, Pharaoh Ants or Fireants constantly re-infest a home or when the ants prefer a soft bait (gel or liquid.) Gourmet Baits can be used in the AntPro baiting system and in Ant Cafe bait stations.

When using ant baits, do not spray or dust with a contact insecticide in the same area! Not only will your bait be contaminated by the insecticides but the spray or dust will kill worker ants before they have a chance to share the baited food with the rest of the colony. The whole point of using a bait is to let the ants do all the work!

A very important part of ant pest control is to correctly identify the ant species that is your pest. Fireants can be controlled with either contact insecticides or baits. Carpenter ants can also be controlled with either type but the new carpenter ant baits are doing the best job. Pharaoh Ants are best controlled by using a variety of ant baits but do not respond well when exposed to ant sprays or insecticide dusts.