Termites in Walls: How to Spot Hidden Activity

The most dangerous termite problems are the ones you cannot see. Subterranean termites can travel through wall cavities, behind plaster and paint, for a long time before any damage shows. By then the colony may have spread to furniture, doors and ceilings.

This guide explains the signs of hidden wall activity.

The short answer

Signs of termites in walls include thin mud tubes running up the wall or from the floor, bubbling, peeling or blistered paint, small cracks or crumbling plaster, a hollow sound when tapped, damp patches without an obvious leak, discarded wings near windows and floors, and tiny pellets or soil-like dust near the skirting. If you see several signs together, a professional inspection is advisable. Termites need moisture and often enter from the soil or a damp area.

Where to look

1. The base of walls and skirting boards
2. Corners and the floor-wall joint
3. Around door and window frames
4. Behind furniture and wardrobes on external walls
5. Near bathrooms, kitchens and leaking pipes
6. Around electrical switchboards and conduits
7. Ground-floor and basement walls

Signs of hidden activity

• Mud tubes: Narrow earthen tunnels the width of a pencil.
• Bubbling or peeling paint: Moisture and tunnelling beneath the surface.
• Hollow sound: When tapped, wood or plaster sounds papery.
• Cracks and crumbling plaster: Sometimes from tunnelling or associated damp.
• Wings: Discarded after a swarm.
• Frass or soil specks: Near baseboards or openings.
• Damp patches: Without a plumbing cause.
• Warped doors and windows: If frames are being damaged.

How to inspect

• Walk around the home in good light, with a flashlight.
• Tap suspect areas gently with a screwdriver handle.
• Look at the bottom 30 cm of walls and behind furniture.
• Photograph signs and note dates.

What not to do

• Do not scrape off all mud tubes before inspection.
• Do not paint over bubbling areas, which hides the evidence and does not stop activity.
• Do not rely on sprays on the surface.

Treatment

A professional determines the type of termite, the extent and the source. Methods may include drilling and injecting walls and floors, soil treatment around the foundation, and treating affected wood. Fixing moisture issues helps prevent recurrence.

When to call a professional

Book an inspection if you see mud tubes or two or more of the other signs. Early treatment limits damage and cost.

Frequently asked questions

Can termites be in walls without damaging them?

They mostly eat wood and paper, but walls can be affected by tunnelling, moisture and plaster damage.

How do I tell damp from termites?

Both can bubble paint. Mud tubes, hollow wood and wings indicate termites. An inspector can confirm.

Do termites go through concrete?

They usually use cracks and joints rather than eating concrete.

How often should I inspect?

At least once a year, and after the monsoon.

This guide is part of IPest's complete resource on termite control. For identification help, prevention and treatment options, see our full termite treatment guide for Bangalore.