Thief ants are one of the smallest species of ants at less than two millimeters long on average, however, queens are slightly larger than the average workers. Both queens and workers are yellowish in color, and workers are equipped with large jaws for carrying food. Native to the United States, these ants can make a home just about anywhere.

The thief ant gets its name from its behavior when foraging for food. Predominantly, instead of finding a food source organically they will piggyback off of other ants so to speak. Thief ants will steal food from other ants’ nests, both items foraged by these other ants and eggs and larvae of the ants whose nest they are raiding. Unlike most ants, they are not drawn to sweet foods. However, thief ants are partial to many items found in our pantries, particularly greasy foods.

Nests of these robbing ants are often positioned very close to other ant nests since these are their primary source of food. Tunnels will connect the two nests for ease of travel. Their nests are much larger and more spacious than what would be expected for such a small-statured ant. Location isn’t of much consequence for these ants, as they will nest anywhere from inside walls of buildings to outdoors under logs and rocks. For these ants, the main deciding factor of nest creation is the proximity of other ants’ nests.

Within these nests, colony size can range into the hundreds of thousands. Larger colonies usually occur when there is less access to food, as more foraging is needed and therefore a higher population of workers. Often, there will be more than one queen within the nest, but no more than 8 queens within the same colony. These queens are mated in the late summer and early fall. Once mated, these queens create new colonies, laying up to 400 eggs daily.

Due to the thief ants’ small size, they are not often even seen within homes. When infestations are discovered, they can be incredibly hard to control again due to the size of the ant and their preference for well-hidden nests.

Did You Know?
These ants also go by the name “grease ant” as they are so fond of grease and greasy foods!