There are 4 goals when treating the exterior for carpenter ants:
#1 Target The Main Colony
First, we apply granular bait around the base of trees. Silver dollar sized dollops are set at the base of the trunk. If there is a crotch in the tree, it is best to place a small pile of bait in the crotch. Otherwise we apply an outer ring of granular bait. Then we spray an inner ring around the base of the tree and up the trunk at least 3 feet. We use Termidor SC, Fuse, Premise, Alpine WSG or Advion WDG for this purpose.
#2 Find And Treat Ant Trails
We also use gel bait on carpenter ant trails. We can only do this when they are visually active. And the weather needs to be right to find them out in numbers during the day. Sometimes we luck out and find a healthy trail on a fence post, landscape timber or on the deck. The best is finding a trail on the house or leading into the home. We can spray the trail or bait under the siding where they are entering. They say carpenter ants are picky eaters. So baiting can be hit or miss. Sometimes they just seem to preoccupied to stop to feed.
#3 Treating Satellite Colonies
We also walk around outside and see if we can inject dust into their satellite nests.
This can be:
- Into door thresholds.
- Under windows.
- Above overhead garage doors.
- Around wooden basement window frames.
- Front porch pillars, soffits, and under siding.
- Railroad ties and fence posts might harbor a satellite colony too.
#4 Treat The Exterior Perimeter Of The Home
Included is an exterior perimeter treatment with a fipronil product, preferably. Fuse or Termidor is best.
- A band around the foundation.
- Under the bottom lip of the siding.
- Around windows and doors.
- Soffits and overhangs.
- Around porches and decks.