Thief ants, or Solenopsis molesta, are a species of ant found throughout America, but are particularly prevalent in the eastern and central states. Thief ants are very small and can be distinguished from other ant species by the two segments found at the end of the antenna. They get their name from their tendency to steal food from the nests of other ants. They usually make their nests in rocks and logs, but they are also known to make their homes in the interstices of walls, skirting boards, cracks and even cupboards. When they do so they are considered a pest and will have to be exterminated.
The thief ant is a yellow-brownish color ant with a typical worker ant measuring approximately 1/32-inch to 1/16-inch (1-1.5 mm). The thief ant is very similar in color and size to the Pharaoh Ant, therefore attention should be paid to the distinguishing features of the thief ant when considering how to get rid of an infestation. Under a microscope or magnifying glass, the thief ant will reveal an antenna of ten segments, two segments at the end of its antenna, no spines on the thorax, two nodes at the lower end of the thorax, and a small stinger at the very bottom of its body.
A typical thief ant queen is a little bigger than the rest and measures around 1/4 inch(6.35mm). A queen will typically lay an average of 105 eggs at a time. These eggs will usually incubate for two weeks to a month during the summer, but the incubation period can last for many months throughout the winter season. They often propagate themselves by splitting the formicary and spreading to different locations, forming new colonies in different sites around an already established center.
The thief ant’s diet is varied and they will feed on anything from immature forms of ants and insects to high protein and greasy foods. They also feed on honeydew, fruit, bread, oil and dairy products.
Thief ants are known to be a nuisance pest and damage walls and other masonry, and are known to contaminate and spoil food. Extermination is troublesome because of their size and adaptability. An infestation can only be handled by a certified and licensed pest controller, who will usually introduce a liquid or gel bait into the infested area. Once the site of thief ant infestation has been located, extermination by a professional can be carried out quickly and painlessly.