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EducationJanuary 29, 20247 min read

Subterranean Termites: How They Destroy Homes from the Ground Up

Subterranean termites cause more structural damage than any other pest in the United States. Learn how they operate, how to spot them, and how to protect your Southern California home.

The Most Destructive Pest in America

Subterranean termites (Reticulitermes hesperus in California) cause an estimated $5 billion in structural damage annually in the United States — more than fires, floods, and storms combined. They are active year-round in Southern California, where the mild climate allows colonies to grow to millions of individuals.

How Subterranean Termites Operate

Unlike drywood termites, subterranean termites live underground in large soil-based colonies. They forage for cellulose (wood) and create mud tubes to travel between the soil and the wood they're consuming, maintaining the moisture they need to survive.

The Colony Structure

A mature subterranean termite colony contains:

  • Queen: Produces up to 30,000 eggs per day
  • Workers: Constitute most of the colony; do all the damage
  • Soldiers: Defend the colony
  • Swarmers (Alates): Reproductive termites that found new colonies

Mud Tubes — The Telltale Sign

Subterranean termites build mud tubes (pencil-width tunnels made of soil, wood, and saliva) to travel between ground and wood. These tubes protect them from desiccation and predators. Finding mud tubes on your foundation, crawl space walls, or piers is the most reliable indicator of an active subterranean termite infestation.

How They Enter Your Home

Subterranean termites enter structures through:

  • Cracks in the foundation or slab
  • Expansion joints in concrete
  • Gaps around plumbing penetrations
  • Direct wood-to-soil contact (the most common entry point)
  • Mud tubes built up foundation walls

Once inside, they consume wood from the inside out, leaving a thin veneer of paint or wood grain intact — making early detection difficult.

The Damage Timeline

TimelineActivity
Year 1–2Colony establishes; workers begin foraging
Year 3–5Active consumption of structural wood
Year 5–10Significant structural compromise possible
Year 10+Major structural failure without treatment

Treatment Options

The most effective treatment for subterranean termites is the Liquid Soil Barrier (Termidor). Termidor (fipronil) is applied as a continuous barrier in the soil around the foundation. Subterranean termites contact Termidor and transfer it throughout the colony — eliminating entire colonies, not just foragers.

For severe infestations with significant structural damage, Tent Fumigation combined with a soil treatment provides comprehensive protection.

Prevention Strategies

  • Eliminate wood-to-soil contact around the structure
  • Fix leaks and moisture problems in crawl spaces
  • Install and maintain proper drainage away from the foundation
  • Never store firewood, lumber, or cardboard against the structure
  • Maintain 6–12 inches of clearance between soil and wood siding

Annual Inspections Are Essential

Because subterranean termites work from below and inside, infestations can go years without visible signs. Annual professional inspections are your best defense.

Contact Ultimate Termite to schedule your inspection. We service all of Orange County, LA County, Inland Empire, and Riverside County.

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