Wood-eating insects can cause significant structural damage to homes and other wooden structures, often going unnoticed until the problem is severe. Understanding these pests, their habits, and the signs of their activity can help homeowners protect their property.
Common Wood-Eating Pests
Several insect species are known for their ability to damage wood, each with distinct characteristics and behaviors. Termites are among the most destructive, particularly subterranean and drywood varieties. Subterranean termites, common across much of the United States, build large underground colonies and need soil contact for moisture. Workers are typically small, about 1/8 inch long, with creamy white bodies, while soldiers have larger, dark heads. Drywood termites infest dry wood directly without needing soil contact. They are larger, ranging from 1/4 to 1 inch, and are pale to light brown.
Carpenter ants are another frequent wood-damaging insect, though their method of damage differs from termites. Carpenter ants are typically black or red and black, with a constricted waist and elbowed antennae. Workers vary in size from 3/8 to 1/2 inch long. They create nests by excavating tunnels and galleries in wood, often preferring damp or decaying wood.
Powderpost beetles are small wood-boring beetles, typically 1/8 to 3/4 inch, and reddish-brown to black. Their C-shaped, whitish larvae are the primary wood feeders. Other wood borers, like the old house borer, are long-horned beetles, 5/8 to 1 1/4 inches, and black or blackish-brown.
Distinguishing Signs of Damage
Identifying the specific pest relies on recognizing the unique signs of damage they leave behind. Subterranean termites build mud tubes, pencil-sized tunnels of soil and wood particles, often on foundations or walls. These tubes provide protected pathways between their underground colonies and wood sources. Drywood termites leave small, loose piles of fecal pellets, called frass, which resemble sawdust. Termites can also make wood sound hollow when tapped. Discarded wings near windows or light sources indicate swarming.
Carpenter ants create clean, smooth galleries within wood, unlike termite tunnels. Piles of wood shavings, resembling sawdust, pushed from their nesting sites are a common sign. Rustling sounds within walls can also indicate a large colony.
Powderpost beetles leave very fine, powdery frass, like flour or talc, often in small piles near their small, round exit holes (1/16 to 1/8 inch), where adult beetles emerged. Wood borers, like the old house borer, create larger, oval-shaped exit holes (1/4 to 3/8 inch) with coarse frass containing wood fragments. Rasping or clicking sounds from larvae feeding within the wood can also indicate an active borer infestation.
How Wood is Damaged
The mechanisms by which these insects compromise wood vary, influencing the extent and appearance of the damage. Termites consume wood directly for nutrition. Their digestive systems contain microorganisms that break down cellulose, the main component of wood, into digestible sugars. This allows them to extract nutrients, causing extensive internal damage that often leaves only a thin outer shell. Subterranean termites typically attack wood in contact with soil or moisture, creating intricate tunnel systems.
Carpenter ants do not consume wood. Instead, they excavate tunnels and galleries to create nesting sites, often preferring damp or decaying wood because it is softer. This excavation weakens the wooden structure, though their damage is typically less uniform than termite damage and often follows the wood grain.
Powderpost beetles and other wood borers cause damage during their larval stage. Adult females lay eggs in wood pores or cracks. Upon hatching, the larvae bore into the wood, creating networks of tunnels as they feed. They fill these tunnels with finely pulverized wood particles and excrement (frass). The larvae develop within the wood before emerging as adult beetles, leaving characteristic exit holes. This internal tunneling can significantly weaken wooden components.
Protecting Your Property
Safeguarding property from wood-eating insects involves a combination of preventative measures and prompt action upon discovering signs of infestation. Controlling moisture is a primary preventative step, as many wood-destroying pests, especially subterranean termites, are attracted to damp conditions. This involves repairing leaky pipes, ensuring proper ventilation in crawl spaces and attics, and maintaining good drainage around the foundation. Removing wood-to-soil contact around the home also deters subterranean termites by eliminating their direct access to structural wood.
Regular inspections of wooden structures, both inside and outside, aid early detection. Sealing cracks and crevices in foundations and exterior walls can prevent insects like drywood termites and carpenter ants from entering. Storing firewood away from the house and elevated off the ground also reduces potential entry points and harborage areas.
If an infestation is suspected, professional intervention is often necessary for significant problems. Consulting a pest management professional is recommended for extensive damage or persistent activity, as they have the expertise and specialized treatments to effectively address the problem and prevent further structural compromise.