It's possible that you don't know you have an ant infestation, but most of the time, you do. The little critters may be marching across you kitchen counters, holding a rally at your pet's food dish or conducting stealth operations in your cupboards or pantry. The kitchen is no place for toxic insect poisons, but you shouldn't need them. You can keep ants out with a variety of safe compounds and control practices.
Vinegar to the Rescue
Although one of the most effective ant-control strategies is to bait them, that takes time, and you may just want the ants to go away pronto. Don't spray them with insecticide; you may kill the ones you see, but they will soon be replaced by reinforcements.
A better strategy is to spray the counters, walls and any other place you see the insects with a one-to-one solution of vinegar and water. It disrupts their ability to detect the pheromones that keep them focused, and they'll disperse. They'll not only disperse, they'll go away, because they don't like vinegar. Spray again every few days to create an ant-free zone. Don't tempt them back: Keep your counters free of sweets and water, and store food in ant-proof containers.
Essential Oils Also Work
Many essential oils also repel ants, and most smell better than vinegar. Some of the most effective include neem, and lemon or orange oil; both of the latter contain d-Limonene, which is a known insecticide. You can buy citrus-based ant control insecticides, but you may find lemon juice just as effective. Clove oil, which contains eugenol -- another fast-acting insecticide -- is another option. Whether you use any of these by themselves or in combination with each other or with vinegar, you don't have to worry about leaving a toxic residue, and you can safely spray regularly.
Get 'Em Where They Live
Ants are resourceful, and there is always a chance they will find a way around the area you've treated and turn up in another part of the house. They may be nesting in the walls or outside, and there are safe ways to eliminate the nest in either case. Start by tracing the trail to the points of entry and sealing these with caulk or wood filler. Look for a trail outside and trace it to the nest, which you can often destroy with boiling water. If you determine the nest to be in the walls, drill a series of 1/4-inch holes for about 2 feet on either side of an entry point and dust food-grade diatomaceous earth or boric acid through the holes with a plastic ketchup container.
The Bait Option
You can control ants with bait in one of two ways. One way is to simply use a sweet or oily substance, such as honey or peanut butter, to attract them away from your kitchen. You need to identify the ants to know which bait will best attract them. Another -- more lethal -- strategy is to lace the bait with boric acid. The ants take the bait back to the nest and feed it to the colony, and the whole colony dies. The bait works best if the concentration of boric acid is less than 5 percent.pdf), although you may have to experiment. You can also simply deploy store-bought boric acid bait stations around your kitchen.