Ants in Tree Roots

While most ants are deemed nuisances when they start invading the home, there are also ants that can infest the roots of trees and make a mess of some backyard landscaping. These ants are typically difficult to get rid of, and while they may in some instances be beneficial, they may also need to be eliminated for the continued health of the tree.

Carpenter ants are the most common type of ant found nesting in the roots of trees. While these ants don't actually eat the wood and root material, they will chew through the wood to hollow out intricate tunnels for nests. Because the ants rely on their ability to chew through wood to make their nests, they typically seek out wet, damaged, diseased or soft woods for nesting purposes. This means exposed roots can be an ideal place for nests, because of the relatively soft material they're composed of.

These ants typically build more than one nest for a single colony. The main nest contains the queen -- with satellite nests for workers, eggs and immature ants.

If the colony of ants is large enough, it can severely impact the health of the tree. Trees rely on their roots to absorb water and nutrients from the soil, and if the colony chews through enough of the roots and damages enough tissue, it can limit the amount of nutrients that the tree can absorb. Roots also serve to stabilize the tree and the soil around it; when enough of this root tissue is compromised, it can also compromise the strength of the tree itself. Roots that are severed can end in a tree that begins to fall.

To get rid of an ant colony that has set up a nest around tree roots, it's necessary to find all the colony's nesting sites and get rid of all the ants. If only one group is eliminated, the queen will produce more eggs to repopulate the satellite nest. If only the parent nest is treated and the satellites remain, some of the workers will begin to lay more eggs.

Carpenter ants typically follow the same trails, and while it might be difficult, it is usually possible to follow them. Nests will typically be in the same area, and will be identifiable by the piles of sawdust outside of the nest entrance. To find the other nests associated with root-dwelling ants, check nearby trees, any fallen logs, stumps or buildings that might contain soft woods.

Getting rid of ants that have set up a home in tree roots can be difficult, especially if the tree has already sustained significant damage. Pesticides and insecticides that are applied directly to the roots of the tree can be absorbed into the plant, causing further damage. There are a number of powders available that are safe to use on and around plants, and this can help kill ants while minimizing damage. Setting up bait traps can also be effective, as the foraging ants will take the poison back to the colony and kill the ants there as well. Some situations may require an exterminator or pest-control professional to safely eliminate the colony quickly to save the tree.