Termite Diagnosis: Do you have termites?

Diagnosing termites can be simple or difficult depending on how much you need to know.

If you turn over a piece of timber on the ground and it is hollowed out and there are hundreds of small whitish insects scurrying around... you have discovered termites! A once-common name was “white ants.”

If you want to be sure they are not really ants instead of termites, you need to look a little more closely. The antennae of ants has an ‘elbow’ halfway along with a knob at the end. Termites have just a ‘string of beads’ all about the same size. The other, easily visible difference is that ants have a definite 3-sections: head, thorax where the legs come from then the separate and definite abdomen. Termites have a definite head, but the thorax and abdomen run together without any constriction between them.

If however you see small, ant-sized flying insects on a summer evening, they could be ants or they could be termites looking for a mate and a potential nesting site. The most noticeable difference is in the size and shape of the wings. Termite wings are the same size; forewing and hindwing are identical. All other insects have a different size/shape forewing to hindwing. Of course the 3-segment versus 2-segment body and the antennae differences still apply.

The diagram of termite versus ant shapes show these differences.

The easily discernible differences—ants have elbowed antennae, a distinct 'waist' between the thorax and abdomen and the flying reproductive ants have a forewing much larger than the hind wing.   Termites shed their equal sized wing shortly after completing their flight. Reproductive termites, and all ants have eyes, but the termite workers and soldiers do not. 

Termite damage diagnosis is also simple.

Termites eat cellulose. This is what wood is made of. So are books, cardboard, linen, and cotton. Sure termites have damaged wool carpets and plastics but they don’t actually like anything but cellulose. And even though there are hundreds of different termite species in Australia and throughout the sub-tropical and tropical world the main termites that cause significant damage to buildings (seasoned wood) are just a few subterraneans — meaning they nest in soil or the inside of hollow trees where they can obtain a constant supply of moisture to maintain the ‘air conditioning’ or reasonably constant temperature and humidity inside the actual nest.

As always, there have to be the exceptions; these are the drywood termites found mostly in the tropics where the relative humidity is high so these termites have adapted to live in their galleries within wooden articles and buildings and they can get enough moisture from the atmosphere.

Diagnosing termite ‘mud’ packing.

Because termites need to keep the humidity up, and because they want to keep their mortal enemy the ants out, termites travel along tunnels made of regurgitated food and if they are eating a piece of wood with splits, they fill the gaps with this ‘mud’ mixture. You may find other sorts of packing between joints in timber but the difference is the termite ‘mud’ is brittle and the cover used by ants has a silken web joining many particles together. The caterpillars of some wood moths do the same thing as they eat out the decayed wood where moisture has been constant in joints.

Diagnosing termite attack point.

You have finished the simple stuff, now you are into the more difficult areas. Termite work is detective work. It keeps experienced pest technicians interested in their jobs because there are many clues from which to deduce the standard detective factors: motive, opportunity and capability.

• Motive is easy. If there is cellulose to be found, scouts will be trying to find it. Their pheromone trail back to their nest becomes the survey markers for the workers to construct the tunnel. Even though the colony may be already attacking food sources in multiple directions, they will continue to seek new feeding options. This instinct was developed to counter the loss of a fallen branch or a log due to fire or flood in those prehistoric forests.
• Opportunity can be a murky thing. You may believe the builder’s claim that the house was constructed to Australian Standards following design rules and the installation of various termite barriers both physical (stainless steel mesh, particulate granite/basalt/glass, metal caps etc) or chemical (impregnated soil, membranes, etc). But, these Standards have been in place (modified and improved) since the 1960s, yet every time you see a TV program showing the standard footage of scurrying termites, a man easily crushing up eaten-out timber framing with one hand and a woman crying... it is because termites bridged a barrier. I cannot count the ways, but here are a few:

Even if a chemical barrier was applied to the soil around the perimeter of a building, it is usually bridged with the addition of new soil, garden mulch, turf put over the chemically treated soil. And even so, the chemicals used do not last much more than 10 years before degrading sufficiently for termites to venture through. Nearly all homes built since the mid 60s have a concrete slab floor.

The termites will not get through the slab unless a crack is wider than about 3mm (most cracks are just hairline). Most termite entry is over the edge of the slab and in through small gaps in the mortar bonding the first course of bricks to the slab. The usual practice is to build the soil up to cover the unsightly edge of the slab and this hides the mud covered termite entry point. Just above the damp course, there are a series of weep holes and termites can build a tunnel up and through any of these, into the framing timbers which all join up.

If your home is built with a suspended flooring (usually timber) you should have underfloor access and you should go under and look for termite tunnels going up the foundation walls or the piers (stumps). Filled in areas such as chimney bases, bathrooms and laundry could camouflage termite entry and these wet areas need special attention.

Then there are the other ‘bridges.’ Irrespective of the floor construction, termites get into buildings because of additions such as pergolas, pool pump screens, new stairs, even dog kennels, cubby houses or a side gate. Too many times, for houses built decades, even a century ago the termite attack occurred only after the addition of a veranda, a granny flat or another form of extension.

Unless you live in tropical dry-wood termite country, the house damaging termites are only going to come from the soil so you look for their opportunity to get from the soil into the building.

• Termites are capable. They hide beneath their mud which makes them capable of traversing long distances under cover. (See the story on termites in the Sydney Town Hall in www.termiteresearch.com.au) The soldiers provide defense against ants but are not much use for anything else. The workers have the weapons: their jaws which are used to chew off a tummy full of wood for transfer back to the nest to feed the royal couple and the nymphs. A new concept of ‘key hole surgery’ is to think of the strength and stability of a building removed gradually through a small tunnel and taken back to the central nest.

	Termites eat cellulose, which is what wood is made of.
They will eat plastic… but don't really like it
	Termites pack up splits and cracks with a dry, brittle 'mud' mixture
Ants weave particles together using a silk webbing
	The first course of bricks will usually be hidden below ground level or paving. If there are any gaps in the mortar, termites scan get through to the timber framework…which all joins together.
Termites built a mud trail to the top of the Sydney Town Hall bell tower in 1959