Thief Ant

Actual Size: 1.5 to 2.2 mm

Characteristics: Brown to yellow in color

Legs: 6

Antennae: Yes

Wings: No

Habitat: Nests are found in exposed soil, under rocks, or in rotting wood. Indoors, nests can be found in woodwork and masonry.


  • Prefer foods with higher protein and fat content.
  • Will nest near other ants, then steal the food and larvae from their neighbor.
  • Since they feed on dead rodents and insects, they can contaminate pantry products as they forage.

Thief Ants in Vermont

Thief ants get their name from their habit of nesting near other, larger ants, then entering their nest to steal food and prey upon larvae. Found throughout much of Vermont, their nests are connected to the nests they rob by galleries that are too small for other ant species to access, but big enough for the tiny worker thief ants to move freely. Feeding on rodents and insects, thief ants also feed on potato chips and other greasy foods. They invade homes through cracks and crevices contaminating stored pantry products and packaged food items.

Thief Ant Habitat

Outdoors, nests are found in exposed soil, under rocks, or in rotting wood. Indoors, they nest in woodwork and masonry. Thief ants enter structures through cracks in the foundation or small openings in woodwork, especially during hot weather. They use electric wires in wall voids to move from one room to another. Commonly found in kitchen areas of homes, thief ants forage in trails seeking greasy foods, proteins, and dairy products.

Thief Ant Behaviors, Threats, or Dangers

Although thief ants rarely bite, they are considered a dangerous pest as they feed on dead rats, mice, and insects, contaminating food as they forage. When they enter homes, thief ants may be carriers of disease-producing organisms, contaminating food sources as they forage. Thief ants trail inside cabinets, on walls, baseboards, tree branches, and shrubs. Due to their small size, they are able to forage into packaged foods.  If a thief ant infestation is suspected, it is recommended to contact a licensed ant exterminator.