Solenopsis molesta, more commonly known as the “thief ant,” is one of the most commonly managed fly pests of homes, and they can be found in every state. A few ants that belong to the Solenopsis genus are the most venomous and medically significant ant species in the US. These dangerous ants include red-imported fire ants, black-imported fire ants, southern fire ants, and tropical fire ants. Although thief ants also belong to the Solenopsis genus, they are not considered dangerous, but they are a tremendous nuisance when they invade homes. Thief ant workers often invade homes to seek out food sources, particularly meat products.
In the natural environment, thief ants live in fields and meadows, but colonies are quite common in urban and suburban areas as well. Thief ants build nests in the ground soil, and one colony can establish several nesting sites that are interconnected by tunnels excavated by workers. Unfortunately, these ants can also establish nests within homes, usually in wall voids, basements, under baseboards, or in foundations. Thief ants feed on insects, honeydew, and seeds, but in urban and suburban areas, these ants regularly seek out food sources within homes. In homes, thief ants consume a variety of human foods, such as meats, vegetables, fruits, breads, sweets, animal fat, and dairy products. Thief ants are commonly referred to as “grease ants” due to their habit of feeding on grease within homes.
Thief ants invade homes at a consistent rate throughout the spring, summer and fall seasons in Arizona, and they can be hard to keep out due to their excessively small size. Thief ant workers that forage within homes are between 1 ½ mm to 2 mm in size, and they have a yellow body with a brown colored head. Their small size allows them to invade stored food products within pantries and kitchen cupboards where they contaminate food with pathogens. In fact, the thief ant is on the “dirty 22” list of insect species that are known to spread pathogens to human food sources. The dirty 22 list was compiled by the Food and Drug Administration to raise awareness about the disease threat posed by common insect pests of homes.
Have you ever found ants in your stored food products?
