My parents live in Houston, and they've tried many things with little success. Every time I hear about a new remedy, I pass it along and they try it. The most recent one was this: pour club soda into the hill. Supposedly, the gasses in the club soda would go deep into the colony and suffocate the ants. My mom says it didn't work at all. I've heard that pouring 3-5 gallons of scalding hot water on a mound wipes out the majority of mounds; those that aren't eliminated have to be treated again after several weeks. I recently received a catalog in the mail for Arbico Organics (800/827-2847 www.arbico-organics.com) and they list three Safer brand products for fire ants. You might give them a try, but although the company calls itself organic, they do carry products that need to be handled very carefully. Organic doesn't necessarily translate into "safe". If you use a product like Amdro from your local garden center, broadcast it over the entire lawn. The worker fire ants collect it and take it back into the mound. It may take six weeks before you'll finally notice that the mound is inactive.