I’d suggest diatomaceous earth. You’d have to scatter it around wherever ant paths are, and then watch when they change paths and keep scattering, but it’s harmless to humans and the environment, so if you’re willing to battle it out with them a bit it works pretty well. I have problems with ants getting into my potted plants outdoors – they climb right up through the holes in the bottoms of the pots. So I just sprinkle diatomaceous earth beneath all the plant pots and that solves the problem.
Boric acid works as well as any nontoxic we have tried and is safe. Create a perimeter.
There are organic sprays that use citrus and are safe around kids and pets. I can’t recall the name of the one we used, but it worked on the flying ants we had in our previous house. I bought it at our local garden center
You may want to try to obtain Amdro at your local hardware store ie. Home Depot, or Lowe’s. Ants love the stuff and it usually kills the entire nest within 2 or 3 days. It’s harmful to pets and kids, though the ants eat it rather quickly. Another suggestion would be to buy Boric Acid it’s harmless to anything that doesn’t have an exoskeliton. It would take much longer to get rid of the ant problem.