Put a line of talcom powder across the place where they are coming in. They won't cross it.
Ants hate cayenne powder and cinnamon. Also, diazanon is basically rose dust, but is harmful to pets and people.
I just buy Terro. It's amazing, not too expensive and works every single time.
I had great success with a 50/50 mixture of sugar and Borax (the powdered laundry soap). However, if you have small children or pets, you have to be careful where you place this mixture, because it can make them sick if it was to be ingested. If you know where the ants are coming in, you can just sprinkle it in that area. The ants are attracted by the sugar, and take pieces back to the nest to share with the colony. This mixture kills the ants, (including the queen), when they eat it. (Or, you can sprinkle the mixture along the outside of your kitchen wall, but the same precaution applies if you have small children or pets).
If more than one colony is entering your kitchen in different places, you may have to sprinkle the mixture in each area.
An alternative is to use peppermint essential oil. You can mix the oil with water, then spray the areas where you see ants coming in. Or you can simply place drops of the oil in those areas. It must be real essential oil, which can be purchased in a natural food store, natural health store, or online. Essential oils don't actually kill ants, but the ants are so repelled by the smell, they won't want to visit your kitchen anymore. LOL! Your kitchen will smell minty for awhile, until the ants find another food source. NOTE: Essential oils should not be inhaled or ingested by cats or other small animals.
Hope this helps. Good luck.
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