Aug 02, 2013 - 03:49 PM
You are dealing with harvester ants, not carpenter ants. Here is a repost from a customer in New Mexico with the same problem -
The black ants you are referring to are known as "Harvester Ants". There are red harvester ants and also black harvester ants, as well as western harvester ants. They are also known as big pinching ants. This ant is very hard to control as their colony structure can consist of up 20,000 worker ants and also penetrate up to 16 or more feet down into the ground, with multiple chambers, tunnels, etc.Baits usually don't work on Harvester ants, as their diet consists of seeds, pollen and insects that they will round up and carry down into the nest. Chemicals pesticides are the only known way to control harvester ants, and I have specifically come up with a way to control them. But before I tell you how, read this - "In the practices of the Navajos – pastoralists and gardeners of the Four Corners region and linguistic descendents of American Northwest Indian peoples – the harvester ants, or “big pinching ants,” had to be placated by elaborate ritual if someone dared to disturb their mound, according to Stephen Welton Taber in The World of the Harvester Ants". :-)
Now that you understand the consequences, the best thing to do is to use Bifenthrin, and mix it in large 5 gallon bucket with a small drip hole (very small drill and drill a hole about 1/16th inch) in the bottom of the bucket. Just make this hole on the side rim facing downward. You may need a truck or a tractor to haul everything to get to the mound.
Basically, mix the Bifen Insecticide at a rate of 1 oz per gallon of water and sit the drip hole of the bucket over the mound entrance. This will allow the Bifen to "drip" into the hole at a slow enough rate to hopefully drain down into the nest without puddling up and running off.
I would recommend that you do this exact procedure for every mound, and preferably have several drip buckets going simultaneously for colonies that are close to each other.
This should certainly kill the ants within the colonies that are getting "drip bucketed", however, it is possible that the harvester ants could have interconnected pathways underground in which they can escape. So if the ants show up somewhere else, repeat the procedure.
Hopefully, this works and the ant gods won't disturb you. Good Luck!