An oak ant infestation can be a major problem, and it can spread if you have multiple oak trees on your property, as many people do. Predominately, if you have an ant infestation in your oak trees, it will be caused by carpenter ants. These are ants that find their way in through wood that’s decayed. The ants then continue on to healthy tissue, where they can cause potentially irreversible damage.
In cases like this, the wood is not actually eaten by the ants. Rather, the oak ant infestation results in extensive galleries being chewed through the tissue to create space for nests. This generally leads to wood shavings and sawdust being created and left outside the nest. These nests must be eliminated quickly, or they could cause structural damage to the tree that cannot be fixed.
One of the primary concerns with an oak ant infestation is the sheer volume of ants it can produce. A single nest in your oak tree could mean thousands of ants and up to 50 queen ants. And that’s just one nest. In addition to the main nest, ants in the surrounding area are likely to form satellite nests, which can lead to multiple ant colonies sharing in the quest for food, making it much harder to identify every nest inside your trees.
Spring is when the queen ants’ quest for trees to infest usually occurs, and this can extend to woodpiles and stumps as well. If infesting a living tree, most ant colonies will force their way into decayed wood and through to living tissue. These ant colonies can also be responsible for infesting hollow doors, voids in walls, and insulation.
Thus, once you have identified that you have an oak tree ant infestation, you need to go about eradicating it immediately.
To begin with, make sure you have the proper safety equipment for the job. Gloves, a dust mask, and safety goggles are all essential before you even consider proceeding. You’ll need a quality drill so that you can drill through the wood and into the nest. And dry diatomaceous earth (DE). DE is a sedimentary layer made up of the fossilized remains of diatoms, or small marine organisms.
Inject the diatomaceous earth into the holes in the nest. This silica-rich powder will dry out the protective wax of the exoskeleton and outer cells of the ants, eggs, and larvae, killing all of them. Just remember, the DE absolutely must be dry or it won’t serve its intended purpose. This is because if the nest’s interior is even the slightest bit damp, the outer cells, eggs, and larvae can withstand the onslaught.
If the nest is damp, you’re likely going to have to use insecticide. While you can attempt to do this yourself, it’s not an easy job, and we highly recommended using a professional tree care company such as Mr. Tree to complete the task. Not only will their certified arborists ensure the job gets done right, but they can determine with certainty if the tree is even healthy enough to undergo a procedure like this or if it has simply become a hazard or is not going to survive and needs to be outright removed.
Unfortunately, even if you can eliminate the main nest, it’s quite possible satellite colonies could be scattered in oak trees all over the area. You may not be able to trace the ants back to all their colonies, and if that’s the case, you’ll need to bait traps. If you employ the traps correctly, the ants will take the bait and bring it back to their colonies to the other ants.
Interestingly, the bait you want to use is different depending on the season, as carpenter ants prefer sugars in the winter and proteins in the summer. So, if it’s winter, find the ant trails and use sweets such as chopped mealworms as bait. If it’s summer, use protein-based food instead, such as cheese.
Regardless of the season, you likely don’t have to make your own bait, as most outdoor stores have effective baits prepared for whichever season you need. These baits are typically made with boric acid, so if administered correctly, they can completely wipe out nests.
It’s also important to remember that while these boric acid–based baits can do the job of wiping out ant nests, they can be highly toxic in humans or other animals if ingested. So it’s imperative they are kept away from children and pets.
In addition to diatomaceous earth and bait, it’s a good idea to use cultural controls to help destroy the original infestation and it’s satellite colonies. To eliminate as many colonies as possible, attempt to locate potential nesting sites and entry points to those sites. Trim tree branches and shrubs so they’re not touching the entrances and don’t provide a path inside the nest. Be sure to get rid of all decayed and damaged branches as well.
Mulch will need to be reduced to 2 to 3 inches deep all around the property and leave a gap between the mulch and the tree trunks (these are good guidelines for mulch even if you don’t have an oak ant infestation). Take out any rotting wood debris or tree stumps. Finally, eliminate anything that necessitates soil-to-wood contact and be sure to store firewood on top of raised racks.
While removing an oak ant infestation is essential to the health of your oak trees, there are more urgent reasons to eliminate the problem as quickly as possible. High on this list is the potential for carpenter ants to migrate to your home, where they can cause structural damage equivalent to that of termites.
To protect your home, seal all possible entry points made by plumbing lines, cables, and other utilities. Any closed areas such as crawl spaces, laundry rooms, basements, and attics should have their air circulation increased substantially to reduce the presence of damp wood and moisture, both of which entice carpenter ants. Leaking faucets and water pipes should be repaired, and clogged downspouts and gutters need to be cleaned. Also, all food sources in and around your home should be removed immediately.