They're in the dead part of the tree. They won't kill the tree.

Not sure if this works on that type of ants, but I read that if you sprinkle freshly ground coffee grounds around, the ants will take them to their nest, and it is poison to them. Your avocado will love the grounds!

No, it doesn't work.

I once sprinkled about a cup of powdered Terro Ant 'stuff' all over and into a huge ant tree-nest and did major damage to the colony. I kept up the attack and eventually won the battle.

I can second that Terro works better than anything else I've ever tried, against ants. Super product!

The fight against ants is neverending, sigh.