It was good to speak with you and to sort out your termite threat. This email is to confirm the main points we covered.
That is a Schedo soldier and worker and there’s a very good chance they are from a nest inside the trunk if it is hollow. The tree does look healthy but by about that size, the chances are the tree has developed a narrow pipe up the inside which could contain a nest. Of course, the nest maybe somewhere else. They don’t build mounds so it almost certainly is below ground level.