How to Kill Thief Ants

Identify the ant. The distinguishing feature between thief and pharaoh ants is in their antennae, and can only be clearly identified under a microscope. The antennae of thief ants have 10 segments with a two-segmented protruding club; pharaoh ants have 12 segments on their antennae with a three-segmented club. If you find a dead ant curled into a ball, it is likely a thief ant.

Determine the location of the nest. The only way to effectively eliminate a thief ant infestation is to destroy the queen and the nest. Thief ants build their nests near other ant nests, in open soil, under pots, bricks and stone or in rotted wood. Nests can be along cracks in foundations and windowsills. Indoors, thief ant nests are harder to locate. Check places like trash bags, closets and cabinets and look for tiny food trails.

Use insecticides to kill outdoor nests. Insecticides pose a risk to other species of insects and plants, often require repeated applications and usually just convinces the ants to relocate. To keep ants from entering buildings, spray insecticides around the perimeter, two to four feet out, focusing on entryways. To treat a nest directly, saturation is necessary.

Use ant bait to kill indoor infestations. The worker ants eat the bait and bring it back to the others as their food supply. Bait kills the ants over a period of weeks and reach the entire colony, unlike insecticides that destroy only sprayed areas.

Call a professional if you have any uncertainties. Pest control experts will ensure an accurate identification, locate the nest and apply the most efficient insecticides with the least risk. They will also ensure that you are using the most effective bait for killing thief ants.