Odorous House Ants

Odorous house ants are small, measuring only 1/16 to 1/8 inch long, with dark brown to black bodies. They have a single hidden node on their petiole that is not easily visible from above. The most distinctive identification trait is the rotten coconut or blue cheese smell they emit when crushed. Their antennae have 12 segments without a club, and they move in well-defined trails.

Odorous house ants are one of the most frequently encountered nuisance pests in Grand Strand homes. They form long, visible trailing lines along kitchen counters, baseboards, window sills, and around pet food bowls. They are particularly active on warm, humid days and especially after the heavy coastal rainstorms common across Myrtle Beach in spring and summer, when deluges flood outdoor nests and drive massive foraging columns indoors within hours. You may notice them clustering around sweet spills, fruit bowls, or sugary residues. Colonies can number in the tens of thousands with multiple queens, making them persistent and difficult to eliminate.

At MBPC, we use targeted liquid ant bait stations placed along active foraging trails, as odorous house ants respond best to sweet-based attractants. The slow-acting bait is carried back to the colony and shared with queens and brood through trophallaxis, collapsing the entire colony over 1-2 weeks. We also apply non-repellent perimeter treatments around the foundation to prevent re-entry, focusing on common entry points along the sandy soil. Given our subtropical coastal climate and susceptibility to heavy rains, repellent sprays are avoided as they scatter the colony and cause budding — where the colony splits into multiple new colonies, worsening the infestation.

In Myrtle Beach, SC, keeping a clean home is the best defense against odorous house ants. Clean up sticky residues and sweet spills immediately, as even a small drop of juice can attract a foraging trail within hours. Store sugar, honey, and syrup in sealed containers. Seal cracks around windows, doors, and where utility lines enter the structure, especially considering the shifting sandy foundations common in the area. Keep mulch beds at least 12 inches from the foundation to discourage nesting near the house, and consider using rock or pine straw mulch instead, as ants tend to prefer woody mulches.

Odorous house ants thrive in the diverse environments of the Grand Strand. Outside, they nest under rocks, mulch, and landscape timbers, often taking advantage of the sandy soil around palmetto trees. They can also be found nesting near salt marshes and tidal creeks. Inside, they favor wall voids, under floors, near hot water pipes, and behind kitchen appliances. In the Myrtle Beach area, they frequently invade homes, especially during the humid spring and fall rainy seasons, seeking shelter from flooding.

Peak activity: Spring-Fall