Yes — both kinds can reach upper floors, they just get there differently. Here's how drywood and subterranean termites end up in second-story walls and attics.
A common assumption is that termites are a ground-floor problem — that if the damage is downstairs, the upstairs is safe. A homeowner in Anaheim Hills was surprised when we found the most active area in her home wasn't the crawlspace but the second-story attic framing. Termites absolutely reach upper floors. The two types that matter in Southern California just take different routes to get there.
Drywood Termites: They Fly Straight to It
Drywood termites don't need to climb from the ground at all — they arrive by air. Winged swarmers fly directly to exposed wood and start a new colony wherever they land, which can just as easily be a second-story eave, an attic rafter, or an upstairs window frame as anything downstairs. In fact, upper floors and attics are among the *most* common places we find drywood activity, because the roofline, fascia, and attic framing offer exactly the exposed, weathered wood swarmers are looking for.
So for drywood termites, "can they reach the second floor" is the wrong question — they often start there.
Subterranean Termites: They Build Their Way Up
Subterranean termites are the ones people picture as ground-bound, and they do nest in the soil. But they're fully capable of reaching upper floors by building mud tubes — protected earthen tunnels — up through the structure. A subterranean colony can travel from the soil, up the foundation, and continue upward inside wall cavities, following the framing to the second story and beyond. It's slower and less common than drywood activity upstairs, but it happens, especially where there's a sustained moisture path.
Our post on how subterranean termites destroy homes covers how those mud tubes work, and drywood vs. subterranean termites covers telling the two apart.
Why the Attic Deserves Attention
Because drywood swarmers target the roofline and attic, the upper structure often carries more risk than homeowners expect — and it's also the area people inspect least. Attic framing, roof sheathing, and second-story eaves are high-value places to check precisely because they're easy to ignore. A flashlight run at a low angle across attic rafters will reveal kickout holes and blistering that a casual look misses.
The Practical Takeaway
Don't treat upper floors as safe by default. If you've found termites downstairs, the upstairs and attic warrant a look too — and if you've found them upstairs, that's completely normal for drywood activity, not a fluke. A whole-structure inspection checks every level, because termites don't respect the assumption that they stay on the ground.
A free inspection covers the full structure — crawlspace to attic — and tells you where the activity actually is.