I have the same problem. Patches of yard with no grass with holes. Ant hills elsewhere.

I recently bought some Sevlin ant,termite, grub pesticide at Menards. It was $8 for 10lbs. It went pretty quickly in my 0.75 acres. Hopefully using the granuals in the grass and spraying the trees with pesticide designed for fruit trees will keep the ants or any other bugs from prospering and making it to the house or killing the trees.

good luck.

The Bayer brand stuff worked will on my sidewalks.