Water has no lasting impact. And vinegar, a solution I'd read about somewhere, didn't work for my mother, as she's often quick to point out.
In a moment of frustration recently, I asked my husband if he'd seen anything on ants in a green flyer we'd gotten in the mail. He had. The solution? Cayenne pepper. I thought he was nuts.
Good thing we have a large bottle. He grabbed the cayenne, went outside by our tomato plants and dumped the cayenne vigorously. "They spread like crazy," he reported.
According to wikihow.com:
You can also apply scents and substances that ants simply don't like for various reasons: vinegar, peppermint oil, cinnamon, black pepper, cayenne pepper, whole cloves, and bay leaves. Some of these might be harmful to pets and irritating to curious children.
Yes, but still better than insecticide when little ones are around.