Published on 06/01/06

Ants marching indoors for water, food

By Sharon Omahen
University of Georgia

As outdoor temperatures get hotter and conditions get drier, humans aren't the only ones coming indoors. Argentine ants are marching inside, too.

"If you have them, you definitely know it," said Dan Suiter, an entomologist with the University of Georgia College of Agricultural and Environmental Sciences. "They travel in trails into kitchens, offices and bathrooms searching for food and water."

Argentine ants are small, just an eighth of an inch long. Native to South America, they were accidentally introduced into the United States more than 100 years ago in New Orleans coffee shipments.


"Since then, they've spread throughout the Southeastern states and into southern California and Hawaii," Suiter said. "They're one of the most pestiferous and most difficult-to-control ants in the U.S. A single colony can consist of hundreds of thousands of ants."

Suiter says the tiny pests travel indoors in the winter, too. But they're much more of a problem in the summer. "They're horrible in the summertime," he said.

During the winter, Argentine ants move inside to survive the cold. They live inside closed spaces, like walls, until spring, when they move outside. By fall, their colonies have grown to a peak.

"When we encounter a drought, like now, while the colonies are growing, they will readily come inside," Suiter said. "As temperatures begin to cool, they will re-enter structures to survive the cold. And next spring the process will start all over again."

Sugar, syrup lovers

Despite this cycle, you can reduce your chances of having these ants in your home by thoroughly rinsing all drink cans before placing them into the garbage or recycling bin and by emptying garbage containers often.

"Like any other time of year, don't leave any food or drinks out," Suiter said. "These ants can find a Coke can with just a little syrup left in it. They love sugar, and they'll show up by the thousands, literally overnight."

Suiter doesn't recommend arming yourself with an over-the-counter insect killer.

"There aren't a lot of good products out there for homeowners to use," he said. "You can spray the ants and get what we call the revenge factor. You kill a lot of ants that way. But you'll never get rid of them, because you haven't hit the nest, where all the queens are."

Use baits or a professional

A bait that can be used indoors is Terro bait, he said. It's a liquid you can buy at most home-improvement and lawn-and-garden stores.

Another effective bait, he said, is Combat Ant-Killing Gel. "It's available in a syringe so you can put small dabs anyplace you see ants," he said.

If you reach a point of desperation, Suiter recommends calling a professional pest control company for help.

"There is one new product, Termidor, that professionals have access to that performs well against Argentine ants," Suiter said. "It's a spray for use outside the home and is not labeled for indoor use."

For more information on controlling pests, call your local UGA Cooperative Extension agent at 1-800-ASK-UGA1. Or order the homeowner edition of the UGA Cooperative Extension Pest Management Handbook.

To order the homeowner handbook, send a $15 check payable to the University of Georgia in care of the UGA Ag Business Office, Room 215 Conner Hall, Athens, GA 30602. Designate your check for the homeowner edition of the Pest Management Handbook.

Sharon Omahen is a news editor with the University of Georgia College of Agricultural and Environmental Sciences.