Drywood vs. Subterranean Termites: How to Tell the Difference
Drywood and subterranean termites can both damage Southern California homes, but they live differently and require different treatment methods.
Drywood termites establish colonies inside wood and do not need contact with the soil. Subterranean termites live underground and travel from the soil into a building.
Correct identification is important. A treatment designed for one type of termite may not control the other.
Drywood vs. Subterranean Termites at a Glance
| Characteristic | Drywood Termites | Subterranean Termites |
|---|---|---|
| Where they live | Inside dry, sound wood | In colonies in the soil |
| Soil contact required | No | Yes |
| Common visible evidence | Hard, six-sided pellets | Earth-colored mud tubes |
| Typical swarm period | Summer and fall | Often spring or fall after rain |
| Colony size | Usually relatively small | May contain hundreds of thousands of termites |
| Common treatment | Local treatment or fumigation | Soil treatment or baiting |
| Controlled by fumigation | Yes | No |
These differences are general guidelines. An inspection is normally required to confirm the termite species and determine the extent of an infestation.
What Are Drywood Termites?
Drywood termites live entirely inside the wood they infest. Unlike subterranean termites, they do not need to travel to the soil for moisture.
They may infest:
- Structural framing
- Fascia boards and roof eaves
- Window and door frames
- Attics
- Patio covers
- Furniture
- Fences and other exterior wood
Because drywood termites remain concealed within wood, homeowners often discover them after finding pellets or seeing winged termites swarm from the building.
Signs of Drywood Termites
Drywood Termite Pellets
Drywood termites create small openings, known as kick-out holes, through which they eject fecal pellets.
The pellets are:
- Hard and dry
- Relatively uniform in size
- Six-sided or visibly ridged under magnification
- Often found in small piles beneath infested wood
Pellet color can vary depending on the wood being consumed. Although these pellets are sometimes described as sawdust, they are not ordinary wood shavings.
Pellets establish that drywood termites have occupied the wood at some point. However, pellets alone cannot determine whether an infestation is currently active or reveal how far it extends.
Drywood Termite Swarmers
Drywood termite swarmers are winged reproductive termites that leave established colonies to begin new ones.
In Southern California, western drywood termites commonly swarm during summer and fall. Swarmers emerging inside a house or piles of discarded wings near windows, doors, and baseboards should be professionally investigated.
Hidden Wood Damage
Drywood termites create chambers and galleries inside wood. The exterior may appear normal even when portions of the interior have been consumed.
Visible signs may include:
- Wood that sounds hollow
- Soft or easily punctured areas
- Small kick-out holes
- Surface blistering
- Damage exposed during repairs or remodeling
What Are Subterranean Termites?
Subterranean termites live in the soil and travel to wooden portions of a building to feed. They typically maintain a connection to the ground for moisture.
These termites can enter through extremely small openings and may travel through cracks, expansion joints, plumbing penetrations, or concealed spaces next to a foundation.
Conditions that can increase the risk of subterranean termite activity include:
- Structural wood touching the soil
- Plumbing or roof leaks
- Poor drainage
- Excess moisture beneath a building
- Buried wood or construction debris
- Tree stumps and stored lumber near the structure
- Stucco or siding that conceals the foundation
Signs of Subterranean Termites
Mud Tubes
Mud tubes, also called shelter tubes, are one of the most recognizable signs of subterranean termites.
Workers construct these tubes from soil, saliva, and small pieces of material. The tubes provide protected passage between an underground colony and a source of wood.
Look for mud tubes along:
- Foundations
- Garage walls
- Crawl spaces
- Plumbing penetrations
- Interior walls
- Areas where wood is close to the ground
Removing a visible tube does not eliminate the underground colony.
Subterranean Termite Swarmers
Common subterranean termites in California often swarm on warm, clear days following soaking rain. Swarming may occur during spring or fall, depending on the species and local conditions.
A swarm in the yard does not automatically mean the house is infested. The colony may be beneath landscaping, a tree stump, buried wood, or another nearby food source.
A large number of swarmers emerging inside the building is more concerning and should be inspected promptly.
Damaged Wood
Subterranean termites often feed along the grain of the wood. Their galleries may contain soil or mud, unlike the cleaner galleries associated with drywood termites.
Possible symptoms include:
- Darkened or blistered wood
- Wood that is easily punctured
- Hollow areas
- Mud inside damaged wood
- Damage near the foundation or other ground-level areas
Termites or Flying Ants?
Both drywood and subterranean termite swarmers can be mistaken for flying ants.
Winged termites generally have:
- Straight or beadlike antennae
- Broad waists
- Four wings of approximately equal length
Winged ants generally have:
- Elbowed antennae
- Narrow or pinched waists
- Front wings that are longer than their rear wings
Save several insects or wings in a sealed container for identification. Clear photographs can also be helpful.
How Are Drywood Termites Treated?
Drywood termite treatment depends on the number and location of the infestations and whether the affected wood is accessible.
Localized Treatment
A localized treatment may be appropriate when an infestation is limited, accessible, and can be accurately located. Treatment may involve drilling into the termite galleries, applying an appropriate product, or removing infested wood.
Local treatment addresses the identified area. It does not provide whole-house control or eliminate colonies that were not located during the inspection.
Whole-Structure Fumigation
Fumigation may be recommended when drywood termites are widespread, located in inaccessible areas, or present in multiple parts of the building.
During fumigation, the structure is enclosed with tarps and treated with a fumigant that penetrates accessible and inaccessible wood throughout the building.
Tiger Termite’s whole-structure drywood termite fumigations include a three-year guarantee. Fumigation leaves no protective residual, so a structure can eventually be reinfested after treatment.
Learn more about whole-structure fumigation.
How Are Subterranean Termites Treated?
Subterranean termites cannot be eliminated through whole-structure fumigation because the main colony remains in the soil.
Treatment may involve:
- Trenching and treating soil next to the foundation
- Drilling through concrete to reach the soil below
- Treating accessible entry points or shelter tubes
- Installing and monitoring termite bait stations
- Removing damaged wood
- Correcting moisture and wood-to-soil conditions
The recommended method depends on the building’s construction, infestation location, soil access, and inspection findings.
Learn more about termite treatment options.
Can a Home Have Both Types of Termites?
Yes. A property can have drywood and subterranean termites at the same time.
Finding drywood termite pellets does not rule out subterranean termite activity elsewhere. Likewise, discovering subterranean mud tubes does not mean the attic, eaves, or other above-ground wood is free from drywood termites.
Each finding must be evaluated separately, and more than one treatment method may be required.
Which Type of Termite Causes More Damage?
Both types can cause significant damage when left untreated.
Subterranean termite colonies are generally much larger and can have numerous workers feeding on a structure. Drywood termite colonies are smaller, but multiple separate colonies may be present throughout a building and remain concealed for years.
The amount of damage depends on how long the termites have been present, the number and location of colonies, available wood, moisture conditions, and other factors.
Visible evidence does not always reveal the complete extent of the damage.
What Should You Do If You Find Termite Evidence?
If you discover pellets, mud tubes, wings, swarmers, or suspicious wood damage:
- Photograph the evidence and its location.
- Save several insects, wings, or pellets.
- Avoid spraying the area.
- Do not seal kick-out holes or emergence points.
- Avoid removing all visible evidence before the inspection.
- Schedule a professional termite inspection.
An inspection can help identify the termite species, locate accessible evidence, evaluate visible damage, and determine which treatment options are appropriate.
Drywood and Subterranean Termite Control in Southern California
Tiger Termite Control has served Chino Hills and surrounding Southern California communities since 1997.
We provide:
- Drywood and subterranean termite inspections
- Localized drywood termite treatments
- Whole-structure fumigation
- Subterranean termite treatments
- Termite damage repairs
You can also view our termite pictures to compare common evidence and damage.
Call Tiger Termite Control at (909) 597-6953 to request an estimate. Free estimates are available when the property is not being sold or refinanced.