Appearance

Carpenter ants are one of the most common wood-destroying pests found in homes and buildings across Long Island, Manhattan, Queens, Brooklyn, and the Bronx. Known for their large size and destructive nesting habits, these ants are often mistaken for termites but have several distinct characteristics.

Adult carpenter ants typically measure between ¼ and ½ inch long, with queens reaching up to ¾ inch. Most species in the New York City area are solid black, though some may appear reddish-black or entirely reddish-brown. They have a smooth, rounded thorax, elbowed antennae, and a clearly defined narrow waist. Winged carpenter ants (called alates) appear in spring and are often confused with termites, but carpenter ants have uneven wings and bent antennae, making them easier to identify.

Common signs of carpenter ants in Long Island and NYC include:

• Large black or red-and-black ants indoors
• Ants crawling near windows, baseboards, or wood structures
• Rustling sounds inside walls
• Frass (wood shavings) near holes or crevices

   

Reproduction

Carpenter ants reproduce through a process that begins in late spring or early summer, when mature colonies release winged ants called alates—the reproductive males and females. These ants leave the nest in a nuptial flight, where they mate mid-air. After mating, the males die, and the fertilized females shed their wings to become queens.

A new carpenter ant queen searches for moist or decaying wood to start a nest, often in wall voids, woodpiles, or other damp, wooden structures. She lays her first eggs and cares for them until they hatch into worker ants. These workers take over foraging and nest-building, allowing the queen to focus entirely on laying more eggs.

Over time, the carpenter ant colony grows and can contain thousands of ants. Once the colony reaches maturity—usually after 3 to 5 years—it begins producing new alates, continuing the reproductive cycle and potentially spreading infestations to other areas.

If you notice large black ants indoors, especially near wood or moisture, it could be a sign of an active carpenter ant infestation. Early detection and professional pest control are essential to prevent structural damage.