I want to get rid of a mass of Agave americana which is considered a noxious weed in our area. They are sited on a steeply sloping site of clay which is set like concrete making it difficult if not impossible for me to deal with as I am no longer as agile as a mountain goat and certainly do not have their stamina. To add another layer of difficulty I have spotted bull ants in the area which I am allergic to. This makes me very jumpy when ever I go to the area as I am really scared of coming into contact with them, I certainly don't want to start doing anything that might make them aggressive. Does anyone know of a sure fire way of killing them with herbicides or perhaps some home remedies?