I personally use the product I found at
http://www.natural-ant-killer.com. It will not harm your plants or
trees and it is 100% effective.

In fact you will find that your trees will flourish because the
solution works as a fertilizer. It does this because it contains a
natural surfactant that breaks down the molecules of water which will
penetrate the waxy coating of the ants and instantly drown them.

At the same time, it works as a fertilizer because the smaller
molecules get down deeper in the soil.

I have to say it is the best thing I have found on the market and I
will never, ever use anything else!

?