Jun 24, 2013 - 01:59 PM
The reason that the ants are going up into the tree could be to gather aphids. They also feed on leaf juices. So the back and forth is a food gathering effort.
Any time you spray for ants, especially carpenter ants, you take a HUGE risk of causing the colony to divide or "bud" into lots of new nests. My advice is to either bait with a short term bait such Advance Carpenter Ant bait, or go with something more long term like the KM Ant Pro System. Always remember that there are more ants on earth than any other creature, and where there are ants, there are usually more ants. Ants are everywhere.
For a quick kill, and not caring whether the ants bud or not, use Bifen Insecticide. Mix it in a bucket and pour about 1-2 gallons of mixed Bifen ( 1 oz per gallon of water) around the base of tree, and saturate the trunk. This will kill the ants on contact.
Then when they show up somewhere else, you can do it again, and again, and again. You get the idea.
Happy ant killing!