Identification of the type of ant you have should be made. There are many different types of ants and with different food preferences. Terro is a liquid ant bait that is a mixture of boric acid and sugar. This bait is excellent for ants that have a sweet tooth. Argentine and house ants prefer oil based baits. If you live in the south, it is possible that you have Argentine ants. House ants are everywhere. Put some ants in a zip lock sandwich bag or other container and freeze them or place in a bottle of rubbing alcohol and take to your local Cooperative Extension Agent for identification. The Agent should be able to provide you with info on ants specific to your area and make recommendations for effective baits.
Ants are usually attracted to structures that have moisture issues. Make sure gutters are clear and downspouts carry water away from structure. Soil should slope away from foundation and carry water away from foundation. There should be no water pooling around foundation when it rains. The only way to know how the structure and landscape handles runoff is to grab the umbrella and go outdoors and inspect during a heavy rain. Inspect plumbing for leaks to assure there are no internal sources of moisture in the structure.
Seal all cracks, crevices, and holes in the structure to eliminate entry into the structure. Spray exterior of structure along foundation and the soil on a monthly basis with residual insecticide. Keep shrubs and foundation plantings pruned back from structure. Pull mulch back several inches away from foundation. Prune tree branches back at least 10 feet from roof to prevent access by insects and animals.
If you have located the entry, seal it to prevent further entry of ants. You can place bait on index cards in the area of entry so that ants will take bait and carry back to the colony where it is fed to others and will kill the colony. If using a granular bait, water the granules to release the insecticide.
If neighbors are also dealing with the ant infestation and have reportedly been doing so for years, it is likely time to call a professional exterminator. Exterminators have access to tools and chemicals that are not available to homeowners. They also have the expertise to deal with insect problems. A contract with an exterminator, who will treat the structure for infestation and make monthly followup preventive treatments along the foundation, would be worth the cost to the home owner association.
http://ohioline.osu.edu/hyg-fact/2000/2064.html