What mud tubes look like, where to find them, and what they tell you about termite activity.
TL;DR: Mud tubes are termite highways between soil and wood; recurring tubes near foundations signal likely activity—schedule an inspection. — Start with early warning signs, then when to call a pro. Prefer to talk? (833) 404-3632.
📋 Assess with LTRS: Location, Timing, Recurrence, Spread — log patterns, not just single clues.
Mud tubes (also called shelter tubes or tunnels) are one of the most visible and reliable signs of subterranean termite activity. These earthen tunnels protect termites as they travel between soil and food sources, maintaining the moisture they need to survive.
Width: Typically 1/4 to 1/2 inch wide (about the width of a pencil), though can be wider for established colonies
Color: Brown, tan, or gray—matches the soil color in your area
Texture: Rough, earthen appearance. Made from soil particles, wood fragments, termite saliva, and feces
Pattern: Usually run vertically but can branch or curve around obstacles
Consistency: Brittle when dry, crumble easily when broken. Moist and pliable when active
Worker termites construct mud tubes by cementing tiny soil particles together with saliva and fecal matter. The tubes:
Purpose: Active pathways for workers traveling to food sources
Appearance: Continuous, well-maintained tubes running from soil to wood
Activity level: High traffic, regularly repaired if damaged
What it means: Active infestation with workers currently foraging
Purpose: Scout tubes built to search for new food sources
Appearance: Thinner, may branch or dead-end. Often incomplete or abandoned
Activity level: May be empty if food wasn't found
What it means: Colony is actively searching for resources, even if this particular tube is abandoned
Purpose: Temporary structures for winged reproductives (swarmers) to exit and re-enter
Appearance: Extend from wood down toward ground, often hanging free
Activity level: Seasonal, most active during swarm season (spring)
What it means: Mature colony producing reproductives, indicating established infestation
Purpose: Built over treated areas or hostile surfaces to bypass barriers
Appearance: May arch over concrete, metal, or chemically treated zones
Activity level: Indicates colony is working around obstacles
What it means: Persistent infestation, possibly circumventing previous treatments
How to do it:
What to look for:
Important: Even if a specific tube is inactive, the colony may still be active elsewhere. Don't assume you're termite-free based on one dry tube.
May indicate early-stage infestation or exploratory activity. Still warrants professional inspection—colonies can be extensive even with minimal visible tubes.
Suggests established colony with active foraging. Multiple pathways indicate significant termite population and ongoing feeding.
Indicates heavy traffic and well-established routes. Mature colonies build wider tubes to accommodate more workers.
Serious concern. Interior tubes suggest extensive infestation, moisture problems, or both. Requires immediate professional attention.
Difference: Wasp nests are smooth, cylindrical, and usually horizontal. Termite tubes are rough, vertical, and narrower.
Difference: Mineral deposits are flat, crystalline, and don't project from the surface. Mud tubes are three-dimensional and raised.
Difference: Webs are delicate, irregular, and easily brushed away. Mud tubes are solid, structured, and firmly attached.
1. Don't panic: Termite damage occurs over months/years. You have time to get professional evaluation.
2. Document thoroughly:
3. Perform break test: Break a small section and check for activity (see above)
4. Don't destroy all evidence: Leave most tubes intact for professional inspection
5. Schedule professional inspection: Contact licensed pest control for species identification and treatment recommendations. Learn about how inspections work.
6. Check for other signs: Look for additional warning signs like discarded wings or frass
Learn more in our year-round prevention guide.
They're a strong indicator, but only a licensed professional can confirm active infestation.
Rebuilt tubes often indicate ongoing activity—book an inspection.
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