When carpenter ants get into trees, they are going into wood that's already dead for some other reason. The "other thing" is what's troubling your tree, not the ants.

I'm with Al on this. On my trees, where there are ants, there are aphids. And actually, Franktank, there is something you can do that, for me, is 100% effective, and that is a product called Tanglefoot. You put a band of corrigated paper around the base of the tree and then slather the Tanglefoot on it. It is the most sticky goo you can imagine. A few brave ants will try to cross it and immediately get stuck and the rest will congregate, run round wildly, and just generally get POed, until they finally give up. It's a show in itself. Don

Ants will farm aphids... I had issues in the past. You can use tangletrap or whatever that sticky goo is call...you put it around the base of the tree. I used it on some peach trees last year because ants were attacking my nearly ripe peaches.

YIKES! That looks like a horror movie!! There is something organic that you can spray on the underside of the leaves, and the topside of course, called BT. What is Bacillus thuringiensis (Bt)? Bacillus thuringiensis, usually referred to as "Bt" (pronounced "bee-tee"), is a naturally occurring bacterium that is lethal to most leaf-eating caterpillars on trees, shrubs, flowers, and vegetables. Bacillus thuringiensis variety kurstaki (B.t.k.) is the general purpose material that homeowners buy when they see just the words Bt or Bacillus thuringiensis without the variety name attached. This is the type of Bt that is appropriate for home landscape use to kill caterpillars. As you can see on the left, there are also varieties designed to kill mosquitoes or potato beetles. Bt is harmless to all other insects, animals, and humans. It comes in powder form for use as a dust or, diluted with water, for use as a foliar spray. It is also available in liquid form. It is sprayed or dusted on leaves of plants that are under attack by caterpillars so that the pests will ingest the bacteria as they eat the leaves. The Bt causes paralysis of the caterpillar's digestive tract, causing it to stop feeding within two hours. Within a day or two, certainly no longer than 72 hours, the caterpillars die. Good luck to you! Suzi