These trees can appear healthy from the outside, yet are an accident waiting to happen. Have a certified arborist inspect your trees every year.
This is a core I took out of sweet gum that we had just removed. From the outside the tree looked fine other than around the base it was developing some odd cavities. I knew the tree had termites from the trails left moving up the bark.
Look how many are on this piece. This piece is only 3"x 3" big.
This is the damage they cause. From the inside, outward. Devastating to the tree!