Found termites outside: what it does and does not mean

Found termites in your garden, a tree or a fence? The Queensland Building and Construction Commission (QBCC) says termites are a problem for homeowners throughout Queensland, and CSIRO notes they are often called white ants.

What matters is how a colony could reach your home. Business Queensland says subterranean termites usually live in the ground and need contact with the soil or a constant source of moisture. A Queensland Government fact sheet on termites in buildings says infestation usually starts from a nest in the ground, usually outside the building perimeter, with termites building galleries over piers or walls to reach the structure from below.

So termites in the yard are a reason to look closer, not a verdict on the house. For first steps after any termite find, see what to do when you find termites.

Tree nests: which ones matter for the house

Termites do nest in trees in Australia, and whether a tree nest matters for your house depends on the species, not the nest alone. CSIRO says Coptotermes colonies may be found under the ground, in tree stumps, in hollow trees and in living trees, and that some Coptotermes species cause severe damage to living trees and to wood used by people. The Queensland Government names Coptotermes acinaciformis as one of the state’s most serious pest species, found throughout Queensland.

Other termites build their nest on the outside of a tree. A Queensland Government booklet says some species, for example in the genera Microcerotermes and Nasutitermes, attach their nest to a tree but keep a soil connection through galleries running down the trunk. A Queensland Government fact sheet says many tree-nesting termites in urban areas do not infest sound seasoned timber. So advice that a tree nest rarely matters and advice to always act can each be true for a different species.

Business Queensland says correct identification takes skill and at least tenfold magnification. For pictures of each nest type, see what termite nests look like.

What you found and what to do: a decision guide

For any termite find outside, the first step is to leave it alone. Queensland Government advice is not to disturb nests, mud tunnels, paths or trails if you think your property has termites. Take photos and note where the activity is; what comes next depends on the find and its distance from the house.

Mulch, stumps, sleepers and fences

Mulch and garden timber against the walls can feed termites and hide the path they take to your house, and old stumps can house a colony, so keep mulch and timber away from the walls and remove old stumps.

Mulch and garden beds

Termites can eat wood and bark mulch: CSIRO lists wood, bark, leaves, grasses and humus among their foods. Mulch against the house is the bigger risk. Queensland Government advice is not to put garden beds, shrubs, trees or bark against the walls, and its fact sheet on termites in buildings says built-up gardens close to a building may promote or conceal termite entry points, particularly with slab-on-ground construction. The same fact sheet says the vertical face of a slab perimeter should be permanently exposed for at least 75 mm unless other barriers are installed. The QBCC adds that garden beds and landscaping can make a home’s termite management system less effective.

Tree stumps

Old tree stumps are worth removing because they can house a colony close to your home. Queensland Government advice is to remove old stumps from the yard, and CSIRO lists tree stumps among the places Coptotermes colonies nest. The Queensland Government also says Coptotermes lacteus, found in southern Queensland, builds mounds usually associated with stumps. If a stump already shows termites, have it checked before anyone grinds or digs it out.

Sleepers, edging and garden timbers

No timber is fully termite proof, according to the Queensland Government, so treat sleepers and edging as possible food. Its fact sheet says termite-resistant and preservative-treated timbers should be considered for new landscaping timbers, and that firewood should not be stored against the building for long periods.

Fences

Termite damage in a fence can mean termites are foraging near the house, but it does not prove they are in it. Queensland Government advice asks public housing tenants to report termite activity in fences and trees around the home. For new fences, its fact sheet says a 50 mm gap between the palings and the soil will minimise the risk of termite infestation.

If the tree is on council or a neighbour’s land

Do not cut, poison or remove a tree you do not own; for a street or park tree, contact your local council. Brisbane City Council says street and park trees are protected under the Natural Assets Local Law 2003, and you need permission to prune, remove or interfere with Council trees above and below the ground. City of Moreton Bay says residents cannot maintain street trees and should contact Council about problem trees on a footpath or in a park. In Logan or any other council area, ask your council before anyone touches a street tree.

Your council may not treat the termites. Redland City Council, for example, says it will not normally treat termite infestations in its trees and is not responsible for resulting damage to private property. It also warns that interfering with a council-owned tree may lead to prosecution under local and state tree protection laws.

If the tree is next door, talk to your neighbour. Either way, a check of your own house is your call.

Is the tree itself safe?

Termites can weaken a tree, but whether a particular tree is safe is a question for a qualified arborist, not a pest manager. Business Queensland says termites create galleries in timber and trees, causing a loss of structural integrity. Signs termites are working in a tree include:

• mud tubes on the bark or at the base of the trunk
• a nest built onto the outside of the trunk or a branch
• a hollow trunk, limb or stump with termites inside

None of these signs tells you how strong the tree still is. Brisbane City Council says its tree inspections are done by a qualified arborist, and Redland City Council uses arborists at AQF Level 5 or higher. For a council tree, ask the council for an assessment. For your own tree, Arboriculture Australia, the industry association, has an arborist directory on its website.

Why you should not knock it down, spray or burn it

Knocking down, spraying or burning a termite nest can make proper treatment harder. A Queensland Government fact sheet says termite workings should not be disturbed until the management approach has been decided, and that premature attempts to repair or replace infested timber may make termites withdraw for a while and hinder treatment. It says to always seek professional advice.

Destroying a visible nest also leaves the rest of the problem. Nests that species such as Nasutitermes and Microcerotermes attach to trees keep a soil connection through galleries down the trunk, a Queensland Government booklet says. The fact sheet on termites in buildings says destroying a nest does not protect a building from other colonies and that regular inspection of the building is essential. When termites are already in the building, destroying a nest is valid only if identification confirms they are the same species as those in the nest.

Tree nests also matter to wildlife: a Queensland Government booklet says termite excavations in trees form part of habitat for bats, birds, reptiles and tree-dwelling mammals. For how licensed treatment works, see how termites are treated.

When a house check makes sense

Get the house checked when termite activity outside is within reach of the house, or when your last termite inspection was more than a year ago. The QBCC advises hiring a licensed pest controller to inspect and report on your property every year, or more often in high hazard areas. Book a check if any apply:

• an active nest or mud leads in a tree, stump or fence close to the house
• mud tubes on walls, piers, stumps or the slab edge
• garden beds, mulch or bark against the walls or over the slab edge
• stumps, sleepers or stacked timber next to the house
• no termite inspection in the last 12 months

A Queensland Government fact sheet says the parts of a building in contact with or close to the soil should be inspected first, and lists foundations, piers or stumps, the subfloor, skirting boards, architraves and roof timbers among the places to look.

Bob Gunn Termite Solutions carries out residential termite inspections across south-east Queensland, including Brisbane. If activity is found, see termite inspection and treatment.

Next steps

If you are weighing up a check, read what affects the cost of a termite inspection. When you are ready, book a residential termite inspection.