Subterranean Termites in San Antonio
Subterranean termites live in the soil around and under San Antonio homes and come up into the wood to feed, traveling inside mud tubes to stay moist. The native species is the one AgriLife tells every Texas homeowner to watch for, and a mature colony can number around 250,000 workers. Because they depend on soil and moisture, controlling them usually focuses on the ground along the foundation and on the damp spots that keep them comfortable.
Think subterranean termites have found your house? Call or text (210) 281-1064 or book an inspection online.
What makes a termite "subterranean"? #
The name means "below ground." AgriLife's subterranean termite guide (E-368) explains that these termites nest in soil, usually within 4 to 6 inches of the surface, and eat cellulose from wood. Outdoors that is useful work, since it breaks down dead wood. The problem starts when the nearest wood is your sill plate.
Texas has two major subterranean termites: the native termite (Reticulitermes) and the introduced Formosan termite. This page focuses on the native one. The Formosan termite has its own page on Formosan termites in San Antonio.
How does a colony grow, and when does it start swarming? #
A new colony starts small and takes years to mature. AgriLife says a colony generally needs three to five years before it begins producing winged swarmers, and by then it usually holds about 250,000 workers. That means a first swarm near your home points to a colony that has been feeding nearby for some time.
The workers, which are blind, wingless and creamy white, do all the eating. Soldiers, with brownish heads and strong jaws, defend the colony and make up only a small part of it.
Swarming is set off by warmth, day length and moisture. In South Texas the flights begin in January and February, earlier than in the Panhandle, and usually take place in daylight, often in the afternoon. Our termite swarmers page covers what to do when it happens.
Why does moisture rule their behavior? #
Subterranean termites lose water quickly and can dry out in open air. That is why they build mud tubes, which keep them in a humid tunnel as they travel from soil to wood. It also explains why leaks matter so much.
AgriLife notes that water from these sources lets termites live away from the soil for longer stretches:
- Plumbing leaks inside walls or under sinks
- Roof leaks and overflowing gutters
- AC condensate lines dripping beside the foundation
- Sprinklers and irrigation soaking the soil against the slab
How do they get into slab and pier-and-beam homes? #
Subterranean termites need a path from the soil to the wood. Common routes:
- Wood touching soil: steps, fence posts tied to the house, trellises, old form boards and grade stakes left after construction
- Foundation cracks: termites build tubes over the outside of the slab or through cracks in it
- Utility and plumbing openings: gaps where pipes and conduit pass through the slab, including the bath trap area under tubs
- Crawl space piers: tubes run straight up piers to the floor framing in pier-and-beam homes
- Soil or mulch above the slab edge: termites can enter behind brick or siding where nobody can see the tubes
For crawl spaces, AgriLife recommends good ventilation and covering about 70% of the ground with 6-mil plastic sheeting to cut moisture.
How are subterranean termites controlled? #
AgriLife describes liquid soil treatment as a continuous treated zone in the soil along and beneath the foundation. Termites can find and exploit any gap in that zone, so the treated zone has to be complete. Some termiticides repel termites, while others are non-repellent, meaning termites tunnel into the treated soil without noticing it. Texas A&M's Insects in the City reports registered termiticides lasting four to ten years in testing.
Bait systems are the other main option. They work slowly through the colony, often over months to more than a year, and must be checked regularly. Once they are removed, the protection ends.
Which option fits depends on the house, the extent of activity and your preferences, and those choices are explained in detail on termite control in San Antonio.
How Pest Trappers handles subterranean termites #
The Pest Trappers technician starts by tracing the termites back toward the soil: checking the slab edge, piers, plumbing openings, bath traps and wet spots for tubes and damage. You get an explanation of where the colony is getting in, which conditions are helping it, and which treatment options make sense, along with the disclosure documents Texas requires. Products are applied following their labels, and pricing is given after the inspection. Termite services are provided by Pest Trappers LLC (TPCL #0887549), which holds TDA's termite category.
We serve San Antonio, Helotes and Schertz, among other nearby towns. To spot the problem early, see signs of termites and the full termite fact sheet.