What are the signs of: Visible mud tubes running up the exterior foundation wall?

Brown or tan pencil-width mud lines climbing the foundation wall. Tubes reappearing within days after you scrape them off. Soft or hollow-sounding wood where the tubes reach the sill plate. Swarms of winged termites near windows or doors in spring. Small piles of discarded wings on windowsills or the garage floor.

Who to call · Leiden

Visible mud tubes running up the exterior foundation wall — Leiden, South Holland

Q: Who should I call for Visible mud tubes running up the exterior foundation wall in Leiden?

For this problem in Leiden, call a Pest Control Technician.

Pencil-width mud tubes running vertically up a foundation wall are highway tunnels built by subterranean termites to travel safely from soil to wood. Even a single tube means an active or recently active colony is feeding on your home's framing. Breaking a tube open may reveal live workers inside. A pest-control technician inspects the full perimeter, probes accessible wood for hidden damage, identifies the species, and applies targeted treatment — typically a liquid termiticide barrier or bait-station system — then schedules follow-up monitoring to confirm the colony is eliminated.