Citronella Ants

Facts, Identification & Control

Latin Name

Lasius interjectus


Workers are yellow and approximately 4 mm long. The queens are about 8 mm long. The workers have a strong lemon-like smell when crushed, which results in their name of citronella ant.

Behavior, Diet & Habits

Citronella ants nest in the soil. Outdoors, they nest under logs and rocks and landscape timbers. They also nest beside foundations and inside of crawlspaces. They make mounds of soil while they dig their galleries underground.

They often make their nests under slabs and porches. Sometimes they push soil up through a crack in a slab while they nest underneath. Homeowners sometimes mistake this soil as a sign of termite activity.

Inside homes, citronella ants nest in areas of high moisture. They often nest in wood that has already been damaged by fungus or termites. If citronella ants invade a home, it may be a sign that there is a moisture problem inside. Finding and solving the moisture problem is a priority.

Citronella ants feed on honeydew that they get from insects that feed on plant roots. Because of this, people seldom see the workers.


Inside the nest, a queen produces new workers and, periodically, winged males and females called swarmers. These winged individuals fly out of the nest and mate. The males perish soon afterward, while the mated females go on to be founding queens for new colonies.

Signs of a Citronella Ant Infestation

Foraging workers and swarms of the winged reproductives are the most likely sign of citronella ant activity. Another possible sign can be earthen mounds generated when the ants nest in soil.


Citronella ants often become a nuisance when the winged ants leave the colonies for their mating flight. Winged ants that emerge through a crack in a slab or a basement wall can be very distressing for the homeowners. These winged ants will not damage anything. A vacuum cleaner is the most effective way to remove them quickly.

More Information

The citronella ant gets its name from the lemon or citronella odor that people smell when they crush a worker. Some people call these ants “large yellow ants” because of their color. In some areas, people call them “moisture ants.” This may be because of the locations the ants choose for nesting. This ant is common from New England to the Pacific Northwest and southward to Florida and Mexico.

Removing potential nesting sites can help discourage citronella ants. Firewood should be stored off the ground. Firewood stacks should be as far from the home as possible.

If a homeowner is experiencing a citronella ant infestation, it is advisable to call a pest control professional.