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Many Washington homeowners notice large holes in the trees on their properties. You may wonder if they are harmful and what causes large holes in tree trunks. Knowing some of the potential causes can make you more informed and encourage you to see assistance from local tree experts.

Timber Tree Service LLC offers professional tree service in Blaine, WA, and can help with your tree problem. Learn more about the potential causes of large tree holes, then give our team a call.

Why Do Tree Trunks Develop Holes?

Trees develop large holes, or tree cavities, when storms hit, when animals make nests, or when bugs and insects attack. 

Natural tree decay can also lead to big holes as the bark starts to break down. Many tree problems can lead to large holes in the trunks, creating a convenient spot for small animals, insects, and pests to call home and possibly harming the structural integrity of the tree. 

Most tree problems begin at the trunk’s base, but issues can occur anywhere within a tree. 

What Causes Large Holes in Tree Trunks?

Several reasons can cause large holes in tree trunks, but here are three of the most popular that may affect you:


Woodpeckers, depending on the type, may eat sap and insects from inside trees. These birds will burrow into tree trunks to obtain the sweet sap and to precisely reach their food. Small holes in the trunk may not be problematic, but they can worsen over time as the birds return for food.

The tree hollows eventually can become large enough to damage its structure and health. You may need to wrap your trunk with burlap or put up reflective, noisy, or colorful objects to deter them from returning to the damaged tree. If you want to know what causes large holes in tree trunks, woodpeckers could be to blame.

Clearwing Moths

Clearwing moths can result in nasty damage to a tree when they use crevices as safety spots for their larvae. The males deposit them into small openings, but the larvae can make them worse as they grow. They will travel throughout the tree to seek shelter from potential predators.

Trees suffering from clearwing moths will lose out on proper water and nutrient distribution.

Bark Beetles

Bark beetles use tree hollows as places to lay eggs, serving as a nest for the larvae to grow into adulthood. They are attracted to trees that are already weak and contribute to their continued decline. Bark beetles may go after trees that have severe decay or disease.

Getting rid of them early on can prevent a total catastrophe. However, your trees may have a small chance of survival if the attack has been ongoing for some time and damage is done.

If you have bark beetles in your tree, or your trees are experiencing health problems, call a professional tree company for immediate help.

Other Potential Causes for Tree Trunk Holes

Although we noted common reasons for holes in tree trunks, you’ll find several other causes for this phenomenon, such as:

  • Tree decay
  • Damage from heavy machinery use
  • Severe weather
  • Collapsing from old age

Receive Professional Tree Care from Timber Tree Service LLC in Bellingham, WA

Now that you know some of what causes large holes in tree trunks, reach out to our friendly team for expert tree care. If insects, animals, or decay have caused major damage to trees on your property, we can help.

Our business proudly serves Bellingham, WA, and the surrounding areas, offering the following services:

  • Tree removal
  • Emergency tree services
  • Tree pruning
  • Tree trimming
  • And more!

Call Timber Tree Service LLC at (360) 441-5033 to obtain your free estimate from our team!

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