The question of whether ants consume wood or simply tunnel through it is a common point of confusion for homeowners, largely because both ants and termites can cause significant damage to wooden structures. While both pests hollow out wood, the fundamental difference lies in their biology and purpose for being inside the material. Understanding this distinction is the first step in identifying and addressing a potential infestation, as their differing behavior leads to very different signs of damage.
Ants Are Excavators, Not Consumers
Ants that damage wood, primarily carpenter ants, do not possess the biological mechanisms necessary to break down and digest cellulose, the main structural component of wood. They do not eat wood for sustenance but instead use their strong mandibles to chew through the fibers, creating smooth, clean tunnels and chambers known as galleries. This excavation is purely for nesting purposes, providing a safe, protected environment for the colony’s queen, eggs, and developing larvae.
Since the wood is not ingested, the chewed material must be discarded. Worker ants push this debris out of the nest through small openings called “kick-out holes.” This discarded material, known as frass, resembles fine sawdust and often contains wood shavings mixed with the bodies of dead insects. Carpenter ants are omnivores, foraging outside the wood for their diet, which consists mainly of sugars like honeydew, plant nectar, and proteins from other insects.
Termites: The True Cellulose Eaters
The insect that does consume wood is the termite, and their ability stems from a unique symbiotic relationship. Termites rely on specialized microorganisms, including protozoa and bacteria, that live within their gut. These internal guests produce the necessary enzymes, such as cellulase, that break down the complex cellulose molecules in wood into simple sugars the termite can absorb and use for energy.
This digestive necessity means termites eat the wood they tunnel through, making their presence a constant feeding activity rather than just a nesting one. Termite species are categorized by their behavior and habitat. For instance, subterranean termites require contact with soil and moisture, often building mud tubes to access wood. Drywood termites live entirely within the wood they consume, obtaining all necessary moisture from the material itself.
Key Differences in Damage and Appearance
The difference in biology leads to distinguishable signs of damage and physical appearance. Termite-damaged wood has a rough, messy appearance inside the galleries, often packed with soil, mud, and fecal matter because they consume the wood. Subterranean termites leave mud tubes on exterior surfaces, which serve as protected pathways from the soil to the wood.
In contrast, carpenter ant damage is characterized by clean, meticulously smooth galleries, appearing as if they were sanded. The primary sign of a carpenter ant infestation is the presence of frass piles near small exit holes in the wood. Physically, a termite has a broad waist, straight antennae, and, when winged, four wings of equal size. Carpenter ants have a distinctly pinched, slender waist, elbowed antennae, and their hind wings are noticeably shorter than their front wings.