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Odorous House Ants

A native species of ant in the United States, Canada and Mexico, the odorous house ants’ common name is from the unusual coconut like odor that the ants release when disturbed.  Odorous house ants are monomorphic, meaning that the workers are all a single size, whereas some other ant species have workers of varying sizes.  Odorous house ant workers are a consistent brown to black color and approximately 1/16 of an inch in length.  Colonies may consist of thousands of workers and typically contain many queens at any given time.  Thriving in a wide range of habitats, odorous house ants are found from sea level up to approximately 10,500 feet in elevation.  Nests are found in various locations including sand, pastures, and grass fields, forests, under stones and logs as well as in houses.  Nests may also be located in stumps and dead trees, in the nests of other animals such as birds and mammals, plant galls and in debris.  Nests in soil lack a defined shape, are shallow and temporary as the ants move frequently.

In a natural setting, odorous house ants collect the excretions from mealybugs, aphids, scale insects and plant hoppers.  In return for the food source, odorous house ants protect these insects from potential predators.  Workers move at a rapid pace and often travel in columns.  When disturbed they scatter, running erratically with their abdomen tipped into the air releasing the alarm pheromone for which they are named.  The pheromone draws additional workers to the site of the distressed ants. Workers will also gather nectar from plants and feed on both live and dead insects.  Odorous house ants have become a major nuisance pest when infesting homes.  They will feed on a wide variety of foods including meats, cooked vegetables, dairy products, fruit juices and pastries.  New colonies are formed when a new queen leaves the colony, either on her own as a foundress queen or with workers.  Nuptial flights in odorous house ants typically occur from June to mid-July.

Control of odorous house ants is a combined effort of both a pest control professional as well as the resident experiencing the infestation.  Interior and exterior chemical control methods are most effective when residents are diligent about keeping the home free of food debris and spills as well as properly storing foods and pet foods to decrease and discourage indoor foraging.  The same is true on the exterior of the home.