Termite nest in a tree or a stump: what it means for the house
A nest in a tree is not a garden problem. It is a colony living within easy foraging distance of your house.
Can termites really nest inside a living tree?
Yes, and in Australia it is common. Several of the subterranean termites that damage houses will hollow out the dead heartwood in the centre of a living eucalypt and build the nest there. The living sapwood around it keeps the tree standing and looking healthy from the outside.
Other species build a visible nest on the outside of a trunk or a branch. Either way the colony is a full colony: it forages out through the soil from that base. And a house standing many tens of metres away is well within reach.
That is the point that matters. The tree is not the problem; the tree is the address. What you have found is a nest, and the question is no longer about the tree at all. It is whether that colony has already found your building.
The two things people actually find
There are two very different sightings, and they get confused constantly.
| What you see | What it usually means | What it does not tell you |
|---|---|---|
| A hard, dark, lumpy nest built on the outside of a trunk or fork, often the size of a football or larger | An arboreal nest. Some species build these routinely; a few of them are of little interest to buildings, others are not | Nothing about whether the species is a house pest. That is decided under a lens, not from the ground |
| Nothing on the outside, but the trunk sounds hollow, mud packing shows in a wound or a pruning cut, or the tree drops limbs | Possibly a nest in the dead heartwood, which is the pattern most associated with damage to nearby houses | Where the foraging galleries run. They are underground and invisible |
We are not going to tell you which species you have from a description or a photo, and neither should anyone else. Species is worked out from soldiers under magnification, and getting it wrong changes what the correct response is.
Why an old stump is the bigger worry
A stump left in the ground after a tree came out is one of the most reliable nest sites there is. And unlike a standing tree it gives you nothing to look at. It is a large volume of dead, damp timber in direct soil contact, in the dark, already colonised by decay. A colony can build up in it quietly for years.
The same applies to the things that behave like stumps: buried form-work never dug out, old timber retaining walls and sleepers, landscaping logs, and fence posts set straight into soil. This is why removing timber from ground contact sits alongside fixing the moisture at the top of every list of conducive conditions.
The mistake that makes it worse
The instinct on finding a nest is to open it up and see what is in there, or to hit it with something from the shed. Do neither.
Disturbing a nest or a working gallery does not kill the colony. It tells the colony that this route is no longer safe. So the colony abandons it and works elsewhere, which in the worst case means moving the pressure from a stump at the back fence to the timber in your walls, where nobody is looking. Some of the species involved will also build satellite nests when the main nest is knocked about. You can turn one known problem into several unknown ones.
It also destroys the evidence. An inspector reads mud, galleries, workings and activity to work out where the colony is and how it is getting about. A nest that has been broken open and sprayed tells them far less.
And it makes the treatment that follows less likely to work, because the products that do the real job depend on live termites carrying them back through the colony. This is the whole reason spraying termites yourself is the wrong move, and it applies just as firmly in the yard as it does indoors.
Does removing the tree fix it?
Not by itself, and the order matters. Taking the tree out removes the nest site, but the foraging galleries in the soil are already there and the colony may have satellite workings elsewhere. Felling the tree and leaving the stump is close to the worst outcome: you have removed the part you could see and left the part they prefer.
There is also a step that catches people out. Many councils control the removal of trees over a certain size or of particular species, so removal may need approval regardless of what is living inside it. Check with your local council before booking anyone, and use an arborist for the tree and a licensed timber pest technician for the colony. They are two trades and they are not interchangeable.
What to do instead
Treat a nest on the property as a reason to have the house looked at, not just the tree. A competent inspection covers the building, the subfloor, the fence line and the trees and stumps in the yard. And it is what turns a sighting into a plan. If it has been more than a year, this is the prompt to book the annual inspection you were going to get around to.
Frequently asked questions
There is a termite nest in a tree at the back of the block. Is my house at risk?
It is close enough to be worth taking seriously. Subterranean colonies forage many tens of metres from the nest through the soil, so a nest anywhere on a suburban block is within range of the building. The nest does not prove the house is affected; it is a reason to have the house inspected.
Can I just cut the tree down?
Removing the tree takes away the nest site but not the colony's soil galleries, and leaving the stump behind leaves them the part they like best. Sort out the colony with a licensed technician first, check whether your council controls removal of that tree, and use an arborist for the felling.
Is the nest on the trunk the same thing as termites in my walls?
Not necessarily. A visible nest on a trunk and concealed workings inside a wall can be different species with very different significance for a building, and neither can be identified from a photograph. That is what the inspection is for.
Does a gum tree in the yard mean I will get termites?
No. Trees are part of the Australian landscape and most of them never host a colony that troubles a house. What raises the risk is a nest plus the conditions that let a colony reach the building unseen: damp soil against the footing, timber in ground contact and a bridged slab edge.
Sources
What this page explains is based on these official sources. If you check one and it does not match what you read here, send it to us and the article gets corrected.
- Queensland Building and Construction Commission. Protect against termites — termite management systems and inspections
- Department of Health, Victoria. Pest control — termites