I discovered that if I use a poison, be it baking powder or chemical, that uses the idea of attracting them to kill them, I attract them faster then the poison is killing them. I end up with more ants then I started out with. I discovered by accident that liquid soap put in their path will keep them away. The same idea as peppermint oil spray... any strong scent that cuts through the scent trail that they leave for each other will confuse them. If you can break the scent trail where they come it, it'll keep them out until they find a way around the interfering scent. Put the scent all around their entry point and they can't find a way around it.