When people see ants wandering around the kitchen counter, their first reaction is “I want those ants GONE!” If the problem has been going on for a while, people sometimes get desperate. The trouble is, when people get desperate, they sometimes fail to think things through. They grab some bug spray and start shooting ants.
But the bug spray only kills the few ants on the counter and soon there are a few more ants to take their place. If there had been time for further reflection, the homeowner might have added: “and I never want to see the ants again!”
Getting rid of ants doesn't have to involve a lot of stinky bug spray. In fact, the first step doesn't require any spray at all. The first step is to inspect the situation. Controlling ants is easier if you know where they live. If the ants are walking in a line, follow them back to their nest. If you find the nest, and if it's outside in the yard, treat it with liquid insecticide. Under the circumstance, it's the quickest treatment, but follow the insecticide's label directions.
If the ants are not walking in line, put a tiny drop of ant bait near the place where they seem to be coming and going. Make sure children and pets can't disturb the bait. If the ants pick up the bait, put out some more. More ant workers will swarm over the bait and soon there will be a crowd of ants eating the bait.
It may take a few days for the ant activity to stop. As long as they are eating, keep the bait filled up.
In the meantime, start looking outside for the things that attracted the ants in the first place. Are the garbage cans and recycling bins in the garage? Move them outside and away from the house. Is there grass, dead leaves, and mulch piled high against the foundation? These are ant-hiding places. Trim the grass and rake the mulch and leaves away from the foundation. (To an ant, a 12″ strip of bare soil next to the foundation probably looks like a desert.)
Are there tree limbs and shrubs growing against the sides of the house? These are perfect bridges into the house. Trim all the limbs so that there is room to walk between the shrubs and the house. If there are dripping faucets or the down spouts drain against the house, get those fixed too. Many ants come for water as much as for food.
Finally, check all of the exterior doors. If you stand outside at night, does light shine under the door? It could be an entrance for ants. If weather-stripping is missing or broken, it should be replaced. If the home has a brick exterior, there may be tiny openings for ventilation (many people call them weep holes). A small piece of plastic screen inserted into those openings can help keep ants from entering that way.