Holes in a tree trunk or limbs can be a sign of termite activity, though termites rarely create visible entry holes the way other wood-boring insects do. Subterranean termites, the most common type found in trees, typically enter through the root system or through cracks in the bark rather than drilling neat, round holes. If you’re seeing small holes in your tree, the damage may actually come from wood-boring beetles or carpenter ants. But if you’re seeing larger cavities, hollow-sounding wood, or mud tubes running along the bark, termites are a strong possibility.
What Termite Damage Looks Like in Trees
Termites work from the inside out, which makes their damage tricky to spot early. Unlike beetles, which leave small round exit holes in bark, termites tend to eat internal wood while leaving the outer shell mostly intact. The signs you’re more likely to notice include sections of bark that sound hollow when tapped, mud tubes (pencil-width tunnels made of soil and saliva) running up the trunk or along exposed roots, and small piles of wood-colored droppings near the base.
Formosan subterranean termites, one of the most aggressive species found in trees, start by feeding on dead heartwood in the center of the trunk. Over time, they hollow out large cavities inside trunks and limbs. You might not see any obvious holes on the surface at all until a limb breaks or a section of bark falls away, revealing the damage underneath. In advanced cases, the tree may lean, shed branches unexpectedly, or develop visible cracks where internal wood has been eaten away.
Do Termites Kill Trees?
Termites in a tree are not an immediate death sentence. Formosan termites typically feed on heartwood, the dense, non-living wood at the center of the trunk, rather than the cambium layer just beneath the bark where nutrients and water flow. Because they leave this living tissue mostly intact, infested trees can continue growing and producing leaves for years while being hollowed out inside.
The real danger is structural, not biological. A tree with a hollowed-out trunk or major limbs loses its ability to withstand wind, ice, and the weight of its own canopy. This dramatically increases the risk of the tree snapping or toppling during storms. A tree that looks perfectly healthy from the outside can collapse without warning if enough internal wood has been consumed.
How Termites Get Into Trees
Subterranean termites live in underground colonies and reach trees through the root system or by building mud tubes from the soil up through cracks, wounds, or old pruning cuts in the bark. They don’t fly to a tree and bore in. Any damage that exposes the inner wood, whether from a lawnmower nick, a broken branch, lightning, or natural decay, gives termites a way in.
Trees that are already stressed, diseased, or partially dead are more attractive targets because they offer softer wood and more moisture. But healthy trees are not immune, especially in areas with large Formosan termite populations. Once a colony establishes itself inside a tree, it can persist for years, gradually expanding the internal cavity.
Risk to Nearby Structures
A termite-infested tree in a remote wooded area is not a concern for your home. But if the infested tree is in your yard or near your property line, the colony can spread. Subterranean termites build mud tubes underground, allowing them to travel from a tree to a home’s foundation without ever being visible on the surface. The same colony feeding inside your oak tree could be exploring toward your house at the same time.
Proximity matters most. A tree within 20 to 30 feet of your home’s foundation creates a realistic pathway for termites to reach the structure. Even if the tree itself seems like a minor issue, it can serve as a staging ground for a much more expensive problem. If you confirm termite activity in a tree close to your house, getting a professional inspection of both the tree and the home’s foundation is the practical next step.
When the Tree Can Be Saved
A tree’s survival depends on how early the infestation is caught and how much internal wood has been lost. Early-stage infestations, where the colony has only begun feeding on a small section of heartwood, are treatable. A pest control professional can apply termiticide to the soil around the tree’s root zone or directly into the trunk to eliminate the colony. The tree won’t regenerate lost heartwood, but it can continue living and growing new wood around the damaged area.
Advanced infestations are a different story. If a large portion of the trunk has been hollowed out, the tree becomes a falling hazard that treatment alone won’t fix. An arborist can assess the remaining wall thickness of the trunk using a rubber mallet test or specialized tools to determine whether the tree still has enough structural wood to stay standing safely. Trees near homes, driveways, power lines, or anywhere people spend time deserve this evaluation, because the consequences of a collapse go well beyond losing the tree.
Telling Termite Holes Apart From Other Insects
If you’re seeing actual round holes in the bark, termites probably aren’t the culprit. Here’s how to tell the common wood-boring insects apart:
- Wood-boring beetles: Leave small, round exit holes (1/16 to 1/4 inch) with fine sawdust around them. These are the most common cause of visible holes in tree bark.
- Carpenter ants: Create smooth, clean galleries inside wood and push out piles of coarse, fibrous sawdust (called frass). You may see larger irregular openings.
- Carpenter bees: Drill perfectly round holes about 1/2 inch in diameter, usually in dead branches or exposed wood rather than living trunks.
- Termites: Rarely leave visible holes. Look instead for mud tubes on the bark surface, hollow-sounding wood, and soft or crumbling areas when you probe with a screwdriver.
If you find mud tubes, you’re dealing with termites. If you find clean round holes with sawdust, you’re likely dealing with beetles or carpenter bees. Both situations warrant attention, but the response is different. Termite infestations in trees near your home carry the added risk of spreading to the structure itself, which makes them the higher priority to address.