Beyond your threshold of frustration? There are methods to treat for this annoying pest that are environmentally sound which can be found at the UC Statewide Integrated Pest Management Program website. Not only will you find information about ants and other pests such as snails, slugs, aphids, etc., you can learn about beneficial insects too.
But, if you are determined to do a spray application with an insecticide yourself, or plan to call a pest management professional, be sure to read about the new Fipronil, a pesticide commonly used to combat ants and other pests, label restrictions at http://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=27509.