Thief Ants

Thief Ant Facts

• Scientific name: Solenopsis molesta, plus a few close relatives also called thief ants
• Location: A native North American ant found across much of the United States, including Florida
• Color: Pale yellow to light golden brown
• Size: About 1/16 inch, or roughly 1.5 to 2 mm

Thief Ant Behavior

Thief ants earned their name. Colonies often nest close to a larger ant species, then run narrow tunnels into the neighbor’s chambers to raid stored food and carry off eggs and larvae to eat. Their small size lets them slip in and out with little resistance. They also scavenge dead ants and other insects.

Telling Thief Ants From Other Tiny Florida Ants

Thief ants are among the smallest ants you’ll find indoors, and in Florida they share kitchens with several other tiny species. More than one kind of thief ant lives here, though they’re often overlooked and rarely the first ant people suspect. Under a magnifying lens, a few features help:

• Antennae: ten segments ending in a two-segment club. Pharaoh ants have a three-segment club.
• Eyes: very small, hard to see even under magnification.
• Waist: two nodes between the middle body section and the abdomen.
• Color: evenly pale yellow to light brown. Pharaoh ants are similar in color but often darker toward the tip of the abdomen. Ghost ants, very common in South Florida homes, have a dark head and middle with a pale, almost see-through abdomen and legs.

Thief ant workers move slowly in thin, steady trails, unlike the fast, erratic ghost ant. Outdoors, they nest in soil, under stones and logs, and often right beside larger ant colonies. Indoors, they settle in wall voids, behind baseboards, under countertops and cabinets, and in small cracks in masonry.

They’re active in warm weather, which in Florida covers much of the year. Most people only notice them when a trail leads to a crumb pile or a greasy pan. If you’ve found a trail and want to know where it goes, see thief ant infestations.