Carpenter Ant

Large ants, 1/4 to 1/2 inch long, with workers varying in size. They are typically black, dark brown, or a combination of black and red. They have a rounded thorax and a single node between the thorax and abdomen. Their antennae are elbowed.

Nocturnal foragers that travel long distances from the nest. They primarily nest in wood, especially wood that is moist or decaying. They don't eat wood but excavate galleries for nesting. Colonies can have thousands of workers and take years to mature.

Moist or decaying wood in trees, fence posts, and structural wood in homes. They prefer areas with water damage: around windows, doors, roof eaves, and in crawl spaces. They can also nest in foam insulation.

Sawdust-like material (frass) near baseboards, windows, or doors. Rustling sounds inside walls. Winged ants (swarmers) emerging indoors in spring or summer. Foraging trails along edges and wires, especially at night. Smooth, clean galleries in damaged wood.

They do not pose a direct health risk to humans, but they can cause significant structural damage if left untreated. They bite if handled, which can be painful but is not dangerous.

Eliminate moisture problems — fix leaks and improve ventilation. Replace water-damaged wood. Trim tree branches away from the home. Store firewood away from the building and elevated off the ground. Seal cracks and gaps around windows and doors. Keep vegetation trimmed away from the foundation.