Scientific Name: Zootermopsis angusticollis | Reviewed by The PCC Research Team
If you have found massive, 1-inch long flying bugs inside your home that look like mutated ants, you are likely looking at a Pacific Dampwood Termite swarm. They are the largest species of termite in North America.
Highly concentrated in Northern California, the Bay Area, and along the foggy coastal regions down to the Central Coast, these unique termites bridge the gap between their Drywood and Subterranean cousins. They do not require contact with the soil, but they absolutely require wood with a high moisture content to survive.
The “Cliff Notes”: Key Takeaways
- Massive Size: The swarmers (Alates) are enormous, measuring between 1/2 inch to a full 1 inch long, with wings twice the length of their body.
- The Moisture Requirement: They cannot survive in bone-dry framing. They almost exclusively attack wood that has been subjected to prolonged water leaks, ground contact, or dry-rot fungus.
- Clumped Frass: Like Drywood termites, they leave fecal pellets. However, because their environment is wet, the pellets stick together in amorphous clumps rather than loose “sand.”
- Chemical-Free Eradication: You rarely need to tent a house for Dampwood termites. Fixing the plumbing leak and replacing the wet wood is usually enough to collapse the colony.
Identification: The Giant Swarmer
Dampwood termites do not have a dedicated “worker” caste. Instead, immature nymphs perform all the labor of chewing the wood. These nymphs are pale, cream-colored, and can reach up to 5/8 of an inch long.
However, homeowners almost never see the nymphs. You will usually discover the colony when they release their massive swarmers in late summer or early fall (typically just before sunset on warm, humid evenings).
| Feature | Pacific Dampwood Termite (Swarmer) |
|---|---|
| Size | Extremely large. From the head to the tip of their folded wings, they measure nearly 1 inch long. |
| Color | Their bodies range from a dark, leathery brown to a reddish-cinnamon color. |
| Wings | Four massive, heavily veined, brownish-tinted wings that are equal in length and extend far past their abdomen. |
To determine if you have Drywood or Dampwood termites, inspect the feces (frass). Drywood termites push out perfectly dry, individual, 6-sided pellets that scatter like fine sand. Dampwood termites live in a very wet environment. Therefore, their pellets stick to the wet gallery walls and clump together into irregular, shapeless masses. If the wood damage feels damp or spongy, it is a Dampwood colony.
Where They Live in California Homes
Pacific Dampwood Termites are heavily reliant on high-moisture conditions and are frequently found living alongside wood-decay fungus (dry rot). In a residential setting, you will usually find them in:
- Plumbing Leaks: Subfloors beneath a leaking shower pan, toilet, or dishwasher line.
- Roof Leaks: Rafters or eaves that have been chronically soaked by a failing roof or clogged gutters.
- Earth-to-Wood Contact: Untreated porch posts, wooden steps, or deck supports that are buried directly into the damp garden soil.
- Crawlspaces: Homes with poor ventilation where earth-moisture continuously condensates on the floor joists.
Eradication & Repair Strategies
Unlike other termite species, dealing with Dampwood termites is usually more of a construction problem than a chemical problem.
Step 1: Eliminate the Moisture Source
If you remove the water, the colony will naturally dehydrate and die. You must fix the leaking pipe, replace the missing roof shingles, or redirect your landscape sprinklers away from the siding. Without addressing the water issue, any chemical treatment will eventually fail.
Step 2: Structural Wood Repair
Because Dampwood termites only infest wood that is already compromised by water or fungus, the structural integrity of the timber is usually destroyed. You will need a licensed contractor to physically cut out the wet, rotted wood and install fresh, dry lumber. Read our Wood Repair Cost Guide here.
Step 3: Bora-Care Preventative Treatment
Before the new wood is sealed behind drywall or paint, it should be treated with a borate solution (like Bora-Care). Borates are registered to kill both termites and the dry-rot fungus that attracts them.
Need a Section 1 Clearance?
If Dampwood termites and dry-rot are stalling your home sale, you need a contractor who can handle both the inspection and the structural repairs to satisfy the lender. Connect with a licensed California WDO expert today.
Call For Termite Inspection: (866) 204-1751Frequently Asked Questions
Q: Do I need to tent my house for Dampwood termites?
A: It is extremely rare. Because Dampwood termite colonies are highly localized to the specific area of the water leak, simply fixing the leak and replacing the rotted wood physically removes the colony from the home. Vikane gas (tenting) is generally reserved for widespread Drywood infestations.
Q: Do they build mud tubes?
A: No. While they share some similarities with Subterranean termites (like requiring high moisture), Dampwood termites do not construct mud tubes over concrete to reach the wood. They fly directly to the wet wood and live inside it.
Q: Are they dangerous to humans?
A: Like all termites, they do not carry diseases, bite humans, or pose a medical threat. The danger is strictly financial, as their presence indicates a severe, underlying water leak that is destroying the structural framing of your home.