We have what are called " odorous ants". We are constantly fighting a battle to keep them out of our upstairs and downstairs bathrooms as well as the kitchen. We have a pest company that we must call to come out at least once every week or every other week. We are not the only ones in our neighborhood to have this problem. Besides what a pest control company can do is there anything else that you can suggest trying.
I wonder what your pest control company is doing that they need to return every couple of weeks? Odorous house ant is a nuisance pest, especially evident in the spring but active all summer. It is a sweet-loving ant, so liquid, sugar-based baits are an effective treatment. Research has shown that a combination of indoor and outdoor baiting, along with application of a residual insecticide, like bifenthrin, fipronil (outdoors) or chlorfenapyr (indoors), to key foraging trails and home entry points does a pretty good job of suppressing ants. Such treatments may need to be reapplied periodically, but they should last longer than a week. A good publication that goes into some depth can be found at https://utextension.tennessee.edu/publications/Documents/PB1629.pdf