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Pest Control/ant colony


I live in San Diego and am dealing with our annual summer attack of Argentine ants. As usual they are a problem in the kitchen, front entrance and living room downstairs. What's different this year is they've invaded new areas including the second floor.

I have used Grant's Stakes with some success in the past so I ordered some. In the meantime I went outside to investigate activity near the house and found 3 conga lines, one of which disappeared into the stucco of the house. Should I assume this means part of the colony is inside the walls, and that I need professional extermination?

By the way I have an indoor cat so I have to be careful.

Hi Theo,  Argentine ants form very large colonies of a few hundred to several hundred thousand workers. Each colony will have multiple queens, with the colony containing about 10% queens and 90% workers. The queen is usually an "egg-laying machine," and can lay thousands of eggs in one season. But unlike other species, the Argentine queen ant will actually help in the grooming and feeding of her young. Males are produced only when colonies are mature and die shortly after mating. The reproductives, those male and female ants with wings, do not leave the colony in a swarm to mate like other ant species.  They usually reach maturity in April or May and mate within the colony.  This protects the ants from harsh weather conditions and predators such as birds, frogs, lizards, and other insects.

New colonies are formed by one or more mated females migrating from the parent colony with a group of workers. Queens are unable to raise a brood alone.  In winter especially, several colonies may combine to form a larger colony in a favorable nesting site, then and divide again in spring or summer.

Argentine ants are one of the trailing ants and may travel 200 feet or more with thousands of ants following each other from the nest to a food source. They prefer sweets and often tend honeydew producing insects. Their diet changes throughout the year. They feed on a number of items and are not considered "picky," since they are reported to feed on sweets, meats, fruits, dairy products, eggs, animal fats and waste, and vegetable oils. While the workers do not eat a lot, foods the ants have fed on may need to be discarded due to contamination because they also feed on garbage, sewage, dead animals and other items that may carry germs.

Outdoors, Argentine ants can be found nesting in moist areas under debris (logs, concrete slabs, trash, and mulch) and in debris (rotten wood, faulty places in trees, refuse piles, bird nests, bee hives, and other places). They can form nests in exposed or covered soil. Argentine ants can form nests under homes and even within the home especially if their outdoor habitat is disrupted.

Indoors, Argentine ants crawl on or in every imaginable place such as stoves, refrigerators, shelves, beds, and clothing. Often looking for moisture, Argentine ants may be found on water pipes, dish washers or other wet locations.

Limit their access into the home by sealing cracks and crevices.  Minimize watering of lawns and flowerbeds which create moist conditions that are favorable for the ants.  Keep vegetation around the home to a minimum and trimmed away from the structure. Trim tree limbs in contact with the structure and electrical wires to remove an easy path for Argentine ants. Do not leave food, especially sweets, sitting on counter tops uncovered.

Insecticides sprays or granules can be applied directly to the nests or around the structure. Make sure all nests are treated. To find ant nests, follow trails from the food source back to the nest.

Indoors, baiting is the preferred treatment for Argentine ants. Place baits at the closest point where ants are entering the structure. Make sure the ants are feeding on the bait.  Do not disturb or spray the ants in the bait stations. You must give the ants a few days to take the bait back to the colony to kill additional workers and the queens. Most ant baits can be found at many grocery and discount stores.  Follow all label directions for proper use of these baits.

In situations where the ant colonies are very large, a pest management professional may be needed. Pest control operators have access to application equipment and professional-use only products that can be quite effective in controlling Argentine ants when applied correctly.  

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Steve Oswalt


My Pest Control and Nuisance Wildlife Removal experience is in Residential, Commercial, Public Housing, Multiple Story Hi Rises, Agricultural facilities. My company is located in Lewisburg, Ohio and our Web sites are


20 years in Pest Control and Nuisance Wildlife Removal business were we provide exclusion services for pest control and nuisance wildlife along with latrine and gauno cleanup.

National Wildlife Control Operators Association's, Bed Bug Professional Group, Pest Management Professional Network, Wildlife Professionals Network, Rodent Management Network

Licensed and Certified in Ohio with the Department of Agriculture and Ohio Division of Wildlife as a Nuisance Wildlife Operator.

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