Why do squirrels dig holes in trees? Good question! Squirrels typically build nests, also known as dreys. In general, squirrels don’t create holes, but they sometimes take advantage of abandoned woodpecker holes or other pre-existing cavities. Additionally, squirrels sometimes gnaw trees, usually where bark is rotten or a dead branch has fallen from the tree, to get to the sweet sap just below the bark. Let’s take a closer look.
Do Squirrels Harm Trees?
Squirrel tree damage is generally limited on healthy trees. However, although it is uncommon, removal of too much bark around the circumference of a branch can block movement of sugars and the branch can be damaged.
Bark may also be damaged if fungal infections enter the damaged wood. Broad-leaved trees are most vulnerable to damage by squirrels. Again, tree damage by squirrels isn’t a common occurrence.
Preventing Squirrels from Making Tree Holes
You may be fighting a losing battle when it comes to preventing squirrels from making tree holes. It’s extremely difficult to remove squirrels and even if you do, more will move into the vacated area. However, you can take steps to limit squirrel tree damage.
The most effective way to limit squirrel tree damage is to care for trees properly, as a healthy tree is very resistant to damage by squirrels. Water, fertilize, and prune properly. Treat insects and diseases as soon they appear.
Wrap the base of the tree with a sheet of tin to prevent squirrels from climbing up the tree. Be sure the top of the tin sheet is at least 5 feet (1.5 m.) from the ground. Keep in mind, however, that this method won’t work if the tree is within jumping distance of structures or other trees. You’ll also need to remove all low-hanging branches.
You can also wrap the base of young trees with 1 inch (2.5 cm.) thick chicken wire to prevent squirrels from digging in the tender bark.
Try spraying trees with squirrel repellant such as a capsaicin-based product. Reapply the repellant if it rains.
If your squirrel problem is out of control, contact your local fish and wildlife department for advice.