Carpenter ants are common household pests often associated with damaging wooden structures. A frequent misconception is that these ants consume wood as a food source, similar to termites. While carpenter ants do tunnel through wood, their interaction with this material is distinct. Understanding their true behavior and the signs of their presence is important for homeowners.
The Truth About Carpenter Ants and Wood
Carpenter ants do not eat wood for sustenance; they are unable to digest cellulose. Instead, they excavate wood to create galleries and tunnels where their colonies reside and reproduce. These smooth, clean galleries provide shelter for the ant colony, including the queen, eggs, larvae, and pupae.
Carpenter ants often prefer to tunnel through wood that is already moist, decaying, or previously damaged, as this material is easier for them to excavate. However, if conditions are suitable, they can extend their tunnels into sound, undamaged wood. Their tunnels have smooth, sandpapered-like surfaces within the wood, unlike the rough, chewed surfaces left by other wood-destroying insects. The wood particles created during excavation are discarded outside the nest, often appearing as fine sawdust.
Identifying Carpenter Ant Activity
Specific signs indicate a carpenter ant infestation. One notable sign is frass, a fine sawdust-like material expelled from their tunnels. This frass typically consists of wood shavings, insect body parts, and sometimes fecal material, accumulating in small piles near activity. Its texture is coarse and uneven, resembling pencil shavings, and can include bits of soil or pupal cocoons.
Carpenter ants create small, neat holes, sometimes called “kick-out holes,” through which they push this frass out of their galleries. These holes are often found on infested wood surfaces. Homeowners might also hear faint rustling or chewing noises from within walls, particularly at night. The sound can be similar to crumpled cellophane. Sighting large, black, red, or brown ants, especially winged swarmers indoors, signals an active infestation. Worker ants range from ¼ to ⅝ inches, and queens up to 9/16 inches.
Distinguishing Carpenter Ants from Termites
Differentiating carpenter ants from termites is important for proper pest management, as they are often confused due to their wood-damaging activities. A primary distinction lies in their physical appearance. Carpenter ants have elbowed antennae, while termites have straight, beaded antennae.
Another visual difference is their waist: carpenter ants possess a constricted, narrow waist between their thorax and abdomen, giving them a segmented appearance. In contrast, termites have a broad waist, making their body appear more uniform and less segmented. When it comes to winged reproductive individuals, carpenter ants have forewings that are longer than their hindwings. Termites, on the other hand, have wings of equal length.
The damage they cause also varies significantly. Carpenter ants create smooth, clean galleries within the wood, often pushing out sawdust-like frass. Conversely, termites consume wood for nutrition, and their damage often includes mud tubes constructed by subterranean termites or wood packed with soil. Termite-damaged wood may also have a honeycomb appearance.