Thief Ants (Solenopsis molesta)
Quick Look Pest Stats
Color: Pale yellow to light or dark brown
Shape: Unevenly rounded, thorax lacks spines
Size: 1.5mm – 2.2mm long
Region: Throughout most of the U.S.
Inside, thief ants nest in small crevices, and woodwork and masonry. They commonly enter structures during hot weather in search of food and use the wires in wall voids to travel from room to room. Outside, they nest in exposed soil or under objects, in trash, rotten wood and cavities in trees.
Thief ants are attracted to greasy and high-protein foods such as nuts, breads, meats, fruits, animal fats, oils and dairy products. When outside, they will also feed on almost anything organic including insects, mealybugs, seeds, and germinating seeds.
Thief ants are one of the smallest household ant species. Most colonies of the smaller species are found in the soil without an entrance hole, unless nuptial flights are occurring. Mating swarms (nuptial flights) begin in late July and end in early fall. Occasionally nests are discovered under stones, but are often found while one is excavating the nest of another ant species. They are considered thief ants because they pilfer the nests of other ants, where they steal brood or food. This ant and the Pharaoh ant are often misidentified because of their similar size and color.
Thief ants may carry disease-inducing organisms to human food, as they have been found feeding on dead rats and mice. They may also serve as intermediate hosts for the poultry tapeworm.
Nest location is critical in the prevention of thief ants; however, they are often difficult to locate. The best way to prevent a thief ant infestation is to consider working with a licensed pest professional to employ a preventative pest management plan.