Mud tubes — also called termite tubes, shelter tubes, or foraging tubes — are the most definitive sign of subterranean termite activity in an Arizona home. Subterranean termites build these pencil-width tunnels from soil particles, termite saliva, and wood fragments to protect themselves from desiccation and predators as they travel between their underground colony and the wood in your home. Finding a mud tube anywhere on your property — on your foundation wall, plumbing, framing, or even on a fence post — means subterranean termites are or have been active in that area. A professional inspection is warranted immediately, even if the tube appears old or dry.

The 4 Types of Termite Mud Tubes

There are four types of mud tubes that Arizona homeowners may encounter. Working tubes (also called foraging tubes) are the most common — they run from the soil up foundation walls, plumbing penetrations, or any surface that provides a path to wood. They are typically 1/4 to 1/2 inch wide and may extend several feet up a wall. Exploratory tubes are thinner, more fragile tubes that branch out from working tubes as termites search for new food sources — they often appear on concrete or masonry surfaces where no wood is present. Drop tubes hang down from wood above, suspended from the ceiling of a crawl space or the underside of a floor — they are a sign of a well-established infestation. Swarm tubes are wider, flattened tubes built near the soil surface in spring and early summer to allow reproductive swarmers to exit the colony — finding swarm tubes means a colony is actively expanding. The presence of any mud tube type warrants a professional inspection.

Prevention & Professional Treatment

When you find a mud tube, resist the urge to break it open or knock it down before calling a professional. Breaking a tube can cause the colony to retreat deeper into the structure and build new tubes in less visible locations, making the infestation harder to treat. If you must break a tube to determine if it is active, break only a small section in the middle and check back in 24–48 hours — active termites will repair the break. Inactive tubes will remain broken. Either way, call a licensed pest control professional for a thorough inspection. Pest Control Bros LLC provides free termite inspections throughout Maricopa, Chandler, Mesa, Tempe, Gilbert, and Casa Grande. Call (520) 424-5244 for same-week service.