Q: Help! Little ants have invaded our kitchen, presumably coming from under the stone patio. We have kids, dogs, cats, and a serious commitment to an organic, no-harmful-chemical way of life. I don’t even really like killing the ants, but how can I keep them out of our house? — Antsy in Mt. Kisco
A: The ants are finding food in your kitchen, so try to keep your floor and counters clean; even a tiny crumb is a temptation. Easier said than done, I know, so onward with remedies.
If you have a stone patio, the ants are probably pavement ants, which are little, dark guys that nest under slabs. Most commercial ant killers are as toxic as their names suggest, and contain a broad-spectrum poison that disrupts bugs’ nervous systems. It also plays havoc with birds, bees, fish … and us, if we accidentally ingest any.
But there are several commercially produced, organic sprays made with plant oils. EcoSMART sells one whose main active ingredient is rosemary oil; Planet Natural makes another from orange peel extract; Safer BioNeem uses neem oil pressed from the seeds of an Indian evergreen tree. All are considered safe for us, but they can kill bees and other beneficial insects. If you’re using them indoors, though, bees are unlikely to come into contact with the spray.
If you want to destroy the nest, you need baits containing something the ants will take home. Those with boric acid are common, but that’s a skin irritant and can be toxic. Diatomaceous earth, a natural substance made up of tiny fossilized plants, comes as a fine powder, like talcum, that you can sprinkle into the patio cracks. It’s harmless to warm-blooded creatures (unless you inhale a lot of it), but it, too, can kill other insects as well. Online chat sites suggest that cornmeal is an effective ant killer and you can sprinkle that around and not hurt a fly. Well, maybe a fly.
There are other folksy remedies. Figure out where the ants are coming in, and put anti-ant substances near their entry. These include cayenne pepper, bay leaves, cinnamon, cloves, and (if you can tolerate the unsightly look) cucumber peels. Sprinkle more along any route they’re using. Mint and pennyroyal are natural ant deterrents, so you might consider growing some in pots on the patio.
I had a similar problem this spring and tried various “irritants” to deter my ants, but they just marched over or around them and continued on their merry way under my door.
What did work, surprisingly, was using a 50-50 solution of water and white vinegar on the counters and wherever the ants were swarming. I just sprayed it on and sponged it off. The vinegar smell went away quite quickly, and the ants went with it. A few days later, a few ventured back and I sprayed again. So far, it’s done the trick.