on the ants, well perhaps...but I know a sawmill operator, who also is a degreed biologist, he took me mover to a large tree on his property, with black ants walking up and down it- and they were depositing chewed up pieces of sawdust at the bottom of the tree. Ants definitely eat away at homes and trees. I had carpenter ants in my garage, and they hollowed out a section of the hard insulation bat in the wall, I removed the insulation section complete like a little ant farm, cut it open and found the queen, and all the small ant eggs.
yes this tree had to go, I don't feel bad about it, after seeing the condition of the trunk, there was little or nothing that could have been done to save it. The top weighed tons, and the bottom was thin and weak. A very dangerous situation A tree is a big, majestic natural organism, in its home environment of the forest, but growing near your home or yard, if falls, it will kill you without remorse, just the same as a bear or wolf would.
there is a lesson to be learned here, I had always maintained my trees, and removed quite a few smaller ones from my property in the past. I paid to get this large tree pruned a few years ago, and removed a few more branches that were dead. But large trees need to be maintained and checked on a regular 6 month to yearly basis, not just when something breaks and falls off them. There's just too much that can go wrong once they get very large and old. The first big branch that fell, was almost as big as the main trunk.
When these trees get this old, the trunk should be checked somehow, for rot. If it's hollow, they should be taken down. The mask here was, the tree was still very much alive, the outer growth ring was feeding what was left of the canopy with water and nutrients.