you could try DE but I'm not sure how successful you will be

DE = Diatomacious Earth

Orange oil mixed with molasses and soap in enough water to drench the pot works every time its all I use in the garden. here's a link to the recipe and a little more information.

Here is a link that might be useful: Organic fire ant control

I use soapy water to kill them , then drench the pot to get the soap out. Often though they are living in the ground below the pot so you may have to move it and then Use Amdro or something to get them.

Hi
Will that work on Carpenter ants?? I use the andro on fire and sugar ants but doesn't seem to work with the carpenters. Thanks gary

The orange oil work with any ant it comes in contact with. It is great to use in the house as its an excellent decreaser / cleaner and it smells great. I also use it against wasp nests and it knocks them down fast.