The term “sugar ant” is a common nickname in the United States, referring to small ant species highly attracted to sweet substances, such as Argentine ants, pavement ants, and odorous house ants. Although they often forage indoors, their colonies are usually established outside in the yard, under pavement, or within landscaping materials. Successfully managing an outdoor sugar ant population requires a multi-step strategy, moving from quick fixes to eliminating the nest, followed by long-term environmental prevention.
Immediate Non-Pesticide Deterrents
For immediate, localized control, simple physical and chemical methods can quickly eliminate foraging ants and disrupt their pheromone trails, which workers use to guide others to food sources. A mixture of water and common liquid dish soap, sprayed directly onto ant trails, kills the insects on contact by dissolving their protective outer waxy layer, leading to dehydration.
Boiling water offers another method for rapid population reduction, particularly when the main ant mound is visible in a non-turf area like a sidewalk crack. Pouring the hot water directly into the entrance of the nest will kill a large number of workers and brood instantly, though it rarely eliminates the entire subterranean colony.
For creating a temporary physical barrier, food-grade diatomaceous earth (DE) can be sprinkled across known entry points or trails. This naturally occurring powder is composed of tiny, sharp fossilized algae that scratch the insect’s exoskeleton, causing desiccation. These deterrents provide immediate relief but do not address the queen or the reproductive core of the nest, making them a temporary solution.
Eliminating the Colony Using Outdoor Baits
The most effective strategy for outdoor sugar ant control involves using slow-acting toxic baits designed to be carried back to the nest. Unlike contact sprays, baits are a delayed-action poison that targets the queen and larval stages. Foraging worker ants consume the bait and transport it back to the colony, feeding it to the queen and other nest mates through trophallaxis.
Liquid or gel baits are highly palatable to sweet-seeking ants and contain a toxic agent, such as boric acid, at a low concentration. This low concentration prevents the ant from dying before it can return to the nest and share the poison. For outdoor use, these gel baits should be placed in protective, weather-resistant bait stations near active ant trails to shield them from rain and sunlight. Granular baits, which are small pellets combined with an insecticide, offer an alternative for treating larger areas of the lawn or garden bed.
Ants’ dietary needs can change rapidly, sometimes shifting from a preference for sugar to a need for protein or fat, so patience is required when using baits. It may take several days or weeks for the toxic material to be fully distributed throughout the colony and lead to its collapse. During this time, do not use contact killers, as this will kill the workers needed to deliver the bait and compromise the elimination process.
Long-Term Habitat Modification
Sustained control of sugar ants depends on making the outdoor environment less appealing for nesting and foraging. Ants require food, moisture, and harborage to thrive, all of which can be managed through environmental modifications.
Eliminating Food Sources
Eliminating accessible food sources is paramount. This includes consistently cleaning up outdoor pet food bowls, securing garbage cans with tight-fitting lids, and rinsing spilled sugary drinks from patios and walkways.
Managing Moisture and Access
Managing moisture levels around the home foundation and garden beds is an effective deterrent, as ants are drawn to damp soil for nesting and water consumption. Homeowners should promptly repair leaky outdoor faucets, ensure that irrigation systems are not overwatering, and maintain proper drainage away from the house structure. Trimming back vegetation, such as tree branches and shrubs, so they do not touch the exterior walls, removes natural bridges ants use for direct access.
Removing Harborage
Replacing organic mulches like wood chips or straw near the foundation with inorganic materials, such as gravel or crushed stone, can discourage nesting activity. Ants prefer to build colonies in loose, organic matter, and the denser structure of inorganic mulch makes it more difficult for them to establish tunnels. Sealing small cracks and crevices in the foundation, sidewalks, and driveways with caulk or mortar also removes protected nesting sites and pathways toward the home’s perimeter.