Control of Nuisance Ants

Use baits, not sprays. Unfortunately, many of us grab a can of Raid at the first sign of ants and just spray away. STOP DOING THIS. Aerosol sprays have their uses but nuisance ant control is not one of them. Sprays are very difficult to use correctly and may end up being messy and ineffective. The best and safest way to control nuisance ants is with baits. While baiting is not the easiest method, it works and is relatively inexpensive. Ants need protein, fats and sugar (carbohydrate) to sustain colony growth. The idea is to attract ants to a bait that they carry back to their colony feeding it to nestmates and the queen. Baits must be attractive to foraging workers and must not be so acutely toxic that workers don't have time to carry it back to the nest and feed it to colony members.
Most of the time baits that contain sugar work best but sometimes fats and protein will be needed for maximum attractiveness. Poison baits consist of two main parts - the bait part (sugar, protein, fat) and the poison or toxicant. One of most effective and safest toxicants is sodium borate or boric acid. Borates exhibit relatively low human toxicity while being highly toxic to insects. Check labels and look for borate or boric acid as the active ingredient.
The trick with baiting is to be certain that the bait you use is acceptable to the ants you are trying to control. This sounds obvious but too often bait stations are put out and never checked for activity. If the ants are ignoring the bait, replace it with another. If the first is sugar-based try one that is fat-based. If your ants are ignoring your homemade bait stations (see below) try one of the pre-packaged bait stations. You can also mix a little vegetable oil with the sugar-based borate baits. The point is to FIND A BAIT YOUR ANTS ACCEPT.
Finally, poison baiting may take awhile to work. Give it a couple of weeks. Continue baiting until you see no more ant activity at your stations. Replace baits if they dry out.