Getting Rid of Ants?

I found this site that tells of a citric acid solution and boric acid, and boiling water and caulking all the holes and other things..spray foam insulation around the water lines are great too. Hope this helps, I have heard ants will not cross over a chalk line, I do not know if this is true.

Here is another bit of advice I found amusing. Most exterminators will tell you it is the water they are attracted to. I think they follow the pipes. You can use some of the spray foam insulation to close off any openings they are coming in through. Here's the best thing I have ever found (and we lived in a house where I tried everything - I thought they were going to carry the house off we had them so bad): mix boric acid with something sweet, like jelly, and spread it on something disposable, like a paper plate.

Sit several out in the bathroom, and keep it closed off from pets and kids. Yes you will attract and kill an unbelievable amount, but just resist the urge to clean them up, and leave them overnight. They will be gone the next day, the other aunts will come and carry them back to their home (heard of "army of ants"? Well, they leave no "soldier" behind) The other ants will feed on them, and kill the entire colony out. I did this one time and had no repeat episodes.

Another thing that works to prevent other occasional ants is cinnamon. I sprinkled some between my window screens and windows so nothing comes in if I open my windows, and lightly misted water, so it doesn't blow all over the place, either.
Good luck!