San Diego is well within the west coast argentine ant super colony that covers 100's of thousands of square miles with literally gazillions of genetically identical little ant clones. When the weather gets hot, they invade houses for the A/C, the better food (donut crumbs instead of a steady diet of roach carcasses), and for the express purpose of pissing off my wife who doesn't seem to accept the fact that ants are not dirty, do not spread disease, and are merely part of our natural ecosystem. Besides this their presence in the house suppresses the population of silverfish and crickets who are also in here for the A/C. So, as usual, it is up to the husband to solve this problem too (see my rat LP bait station review). What works like a charm is a spray of the house and garden perimeters with Termidor SC, then use sodium borate based ant bait stations inside the house wherever the ant scouts are observed. If the ants have established a breeding colony satellite within your home (remember you have already sprayed outside), the scouts will report back to the outpost the presence of yummy food and more workers will be dispatched to find it again, following the scout's pheromone trails. BTW, that's why the wife should be restrained, if possible, from either killing the scouts or using 409 to wipe where the scouts have been. The workers will return to their nest and throw up the sodium borate solution into their little ant grub babies' mouths, killing them too. In this manner the outpost in the house is eliminated and the barrier outside keeps new ants from coming in again. Obviously, if you put the bait station down next to the scout and you don't see any more ants, then you probably didn't have a colony in the house at all. BUT IF YOU DIDN'T SPRAY THE HOUSE PERIMETER FIRST, YOU HAVE JUST INVITED THEM INTO YOUR HOUSE!!! The combined method works well. I went two years between treating. This combined method works great.