I have very small ants making their home underneath my liner and concrete decking. They're not carpenter ants and seem too small to do any real damage. They're just a few millimeters in length. That said, I'd rather them find a new home. Obviously, it's not a good idea to use pesticides anywhere near the pool. So, other solutions are sought. I used Borax a couple times. It works to clear them from the nest sight, but they later re-appeared on the other side of the pool. I'm going to try some food grade DE powder next. Any other ideas?