How do I know if my building has termites?

What are the signs that my building has a termite problem?

Some common signs of termite activity in commercial buildings include: 

• Mud tubes: Subterranean termites build pencil-width tubes of soil and debris along walls, foundations, and floor joists to travel between the colony and their food source. These are one of the most reliable indicators of activity.
• Swarmer wings: Discarded wings from flying termites near windowsills, doorways, or light fixtures often indicate that a swarm has recently occurred nearby.
• Hollow-sounding wood: Tap wooden surfaces, door frames, hardwood floors, or skirting boards. A hollow sound can indicate that termites have been feeding inside.
• Blistered or bubbling paint: This can look similar to water damage but may indicate termite activity beneath the surface.
• Frass: Termite droppings, known as frass, look like small pellets or sawdust and are a sign of drywood termite activity.
• Tight-fitting doors or windows: As termites damage wood and produce moisture, door and window frames can warp, making them harder to open or close.
• Visible termite damage: In more advanced cases, you may see wood that appears crushed, honeycombed, or structurally compromised.

Termites are often called "silent destroyers" for good reason. They can be active inside walls, floors, and structural timbers for months or even years before any visible signs appear. In a commercial building, given the potentially large footprint, the damage can be significant by the time it's discovered. Knowing what to look for is the first step in catching a problem early.

Our signs of termites guide covers these indicators in more detail and can help you understand what to look for during routine walkthroughs. Pay particular attention to basements, crawl spaces, utility rooms, areas where wood meets soil, and any part of the building that has experienced moisture issues. These are the areas where termites are most likely to establish activity first.

If you spot any of these signs, it’s best to get a termite control technician to conduct a full inspection.