Ants in Your Tree in Richmond Hill?

A line of big black ants marching up and down the trunk is enough to make anyone nervous. People often assume the ants are eating the tree. They aren’t. Ants are a clue, and reading that clue tells you whether you have a nuisance on your hands or rot hiding in the trunk.

Which Ants Are You Seeing?

Two very different kinds of ant show up on Richmond Hill trees, and they mean different things.

Small Ants Heading for the Leaves

Small brown or black ants climbing high into the canopy are usually tending aphids. Aphids feed on leaves and give off a sweet, sticky liquid, and the ants protect them to collect it. You might notice sticky leaves, a shiny film on the patio table or black sooty mould. It is messy, but it rarely harms a healthy tree.

Large Black Carpenter Ants

Carpenter ants are big, often 6 to 13 mm, and usually black or black and red. They don’t eat wood. They chew galleries through wood that is already damp and softened by rot, and push the debris out as coarse sawdust called frass. A healthy, solid trunk is too hard for them. If they are nesting in your tree, decay got there first.

Reading the Signs Around the Nest

Carpenter ants point to rot, but the amount of rot varies a lot. These checks help you judge it.

• Where are they going in? Ants using an old wound or branch stub high up suggest a pocket of decay. Ants entering at the base or root flare suggest rot near the anchor point, which matters more.
• Is there frass? Fine sawdust piling at the base or spilling from a crack means active galleries inside.
• Does it sound hollow? Knock firmly on the trunk around the entry point. A dull, hollow note compared with the rest of the trunk means missing wood.
• Is the crown healthy? A full canopy with no dead branches is reassuring. Dieback at the top together with ants is not.
• What is in reach? Decay in a maple that hangs over your bedroom matters more than the same decay in a tree by the back fence.

Simple Steps on Your End

Take photos of where the ants go in and any sawdust piles. Keep firewood, old stumps and damp lumber away from the house, since carpenter ants nest in those too. If branches rest on the roof or siding, they give ants a bridge into the house, and cutting them back is worth doing whether or not the tree has ants.

Don’t drill into the trunk to find the nest, and don’t pour anything into the hole. That only opens a fresh wound for more rot. Pesticides aren’t part of our work; that takes an applicator with a licence, and poison does nothing about the soft wood that attracted the ants.

Ants and Trees Around Richmond Hill

Carpenter ants love moisture, so you see them most in older trees with old wounds: the big silver maples and willows near Mill Pond, mature street maples in Richvale and Crosby, and trees on wooded lots near the ravines and creeks that feed the Rouge and Don rivers. Willows and silver maples rot quickly once wounded, which makes them favourite nesting sites.

Up on the moraine, where the ground turns sandy near Lake Wilcox, trees dry out fast in July and August. Stressed trees seal wounds more slowly, and that gives decay a head start.

What Usually Happens Next

When Scott comes out, he checks where the ants are working, sounds the trunk for solid wood, and looks at what sits below the tree. Most trees with ants end up in one of three groups.

• Small, contained decay high in a limb. We take that limb out and the problem goes with it.
• Decay in the trunk with a thick, sound shell. The tree can stay, often with a lighter crown, and you watch it from year to year.
• Rot low in the trunk, or very little solid wood left, on a tree that could reach the house. That is a safety problem, and taking the tree down is usually the honest answer.

For that last group, our dead and decaying tree removal work lowers the tree piece by piece and leaves the yard tidy. Mind the permit rule first: Richmond Hill’s Tree Preservation By-law 19-25 protects private trees 15 cm or wider at chest height, so the City has to approve the work. Its process for hazardous trees can differ, so ask.

Getting a Second Pair of Eyes

Seeing sawdust, or ants pouring out of a trunk near the house? Text Scott at (289) 475-5822 with a picture of where they go in, or just call. We’re around seven days a week from 8 in the morning to 8 at night, we’ll visit that day, and the quote costs nothing. If the ants turn out to be harmless aphid farmers, you’ll hear that from us too.