We live on a hill... a tiny hill and people look at me funny when I say that, but really the water drains away from the house in four directions... that's a hill or a rise in my books... and the soil is very dry. SO lots and lots of ants come to live in our dry soil. We've tried every ecologically friendly remedy we could find... no luck.
So we gave in and called the Orkin man. Instant results and guaranteed for a year. We could use the garden and deck within a few hours and what they used is odourless so the doggies weren't even attracted to the dead anthills for a sniff.
I have tried so hard to be ecologically responsible but sometimes you gotta do what you gotta do.