What does sawdust at the base of my tree mean?

Question:

There is a pile of sawdust-like material at the base of a large tree. What could be the problem?

Answer:

It’s likely the pile of sawdust-like material was produced by carpenter ants.  Carpenter ants commonly nest inside older, hollow trees or in trees with dead limbs or branches.  Carpenter ants do not eat wood.  However, they excavate some of the soft, decaying wood inside the tree to form their nest cavity.  The sawdust-like material is often deposited in a pile at the base of the tree.  Carpenter ants do not seriously harm trees.  Control of carpenter is not essential for the tree's health.  However, extensive wood decay weakens a tree and makes it more susceptible to storm damage.