Despite successes in controlling fire ant invasions with the predatory phorid fly (adult shown above in a file photo), it's unlikely that fire ants will be totally ousted from the southern United States, experts say.

"They were still talking about complete eradication back in the early to mid 1970s," said Donald Feener, an ant ecologist at the University of Utah. "You're not going to eradicate something that is that widespread and that abundant unless you have all-out chemical warfare."