There's no simple answer for this one. Probably more than two years. Some older termiticide sprays, like chlorpyrifos, can degrade very quickly. (Apologies for using the chemical names rather than product names - see later. Others such as bifenthrin and fipronil will last longer. Fipronil lasts a disturbingly long time in the environment. Imidacloprid is somewhere in between. Chlorantraniliprole is a bit new but should last at least as long as imidacloprid. The rate at which a poison degrades varies enormously over short distances. The main factors are: the initial dose applied, temperatures, rainfall, soil type, alkalinity, presence of plants, applicator skill and the chemical properties. Then there's disturbance from floods, gardeners and burrowing animals. The chemicals will nearly always last a lot longer under your house than around it. With a chemical, you might get ten years or more service life under the house but find it fails in  two to five years around the outside. Some poisons, like imidacloprid, can be happily sucked up by plant roots so that while you might have no aphids on your roses for a while. There's always a risk the poioned-soil barrier mightn't last as long as you'd hoped.

--You'll note I used the chemical names rather than product names. There's likely to be some variation between products that rely on the same chemical poison (=termiticide. or 'active') but have slightly different formulations or origins. Even the difference in the size of the tiny particles of poison can make a big difference. You can get your soil tested to see what's there or you can rely on the experience of your pest manager to tell you when another dose is needed. Try not to over do it with applications as more is not necessarily any better but usually carries higher risks.

In this answer summary,  I've left out the product names. I don't like going to court. "Fumigation" is when they wrap your house and gas it, that is to use a penetrating gas to enter every place that a termite might be. In general, the answer is a simple, no spot treatment as effective as fumigation, regardless of the spot treatment used.. Fumigation means that a lightweight poison gas seeps right through your home and into everything, even right into damaged wood. It is used on drywood termites. Fumigation is generally thought to be bad for the atmosphere and it uses a lot of toxin. It does have the benefit of wiping out every last termite that's exposed. It is the best treatment for drywood termites. It is nearly always useless against subterranean termites because these can retreat to ground when disturbed (but good if they can't get away, such as in a wooden boat). Whole-of-house heating comes close and is perhaps more environmentally responsible (if the plastics in your house can take the heat). Spot treatments can work really well but the technician has to find and treat every bit of infested timber. There may be hundreds of little drywood termite colonies in the one building. Borates and other preservatives do have something over fumigation in that they keep working after the wrappings come off (you wouldn't ever want a gas that hung around) and so these provide some ongoing ('residual') protection. Bottom line is that it depends on the extent and nature of the infestation and that means that you'll probably need to rely on a specialist timber pest inspector to help you decide what's best for you.

Hopefully, your home comes with pre-installed termite management and hopefully this will be a least-toxic alternative. A life-of-structure, physical management system that doesn't rely on any poisons is best. If you don’t already know what's been done, please ask the builder or vendor how termite risks have been managed. Simple things can help prevent termite attacks. Without a management system you usually can’t see what termites are attacking. It is very important that you don’t do anything to make life easier for the termites. Make your future life easier instead. If your new home was somebody else's beforehand, you should have had a termite inspection before purchasing but either way, once you are ready to move in, it may be a good idea to get a more thorough inspection than can be done in a house that's dressed-up-for-sale.

In most places, pest termites are native animals, part of the wildlife and while they are allowed to be killed, chances are that there are that will just keep arriving. In parts of the Eastern USA, you can have upwards of 25 separate Reticulitermes colonies working a garden.

Keeping termites in the garden largely means leaving them alone. Keeping those termites out of you house can be harder. Subterranean pest termites, particularly some species of Coptotermes and Reticulitermes, should not be encouraged near structures. To be sure, you need to know what species you have and how much of a risk they are in your area. Your specialist termite inspector can help you there.

If your garden has dampwood termites, these are much less likely to enter a well-built, properly drained building than the tunnel-happy subterranean termites. If you live in an area of known drywood termite hazard, then you'll be slightly increasing your risks if you leave known drywood colonies alone.

Keeping the subterranean termites from finding the house is best done by keeping things dry and inspectable. See my Avoid page.

Things will be easier if your house has an effective termite management system in place, especially proper long-life physical barrier components (which don't rely on a chemical deterrent). If your house has soil poison ('termiticide'), then the non-repellent poisons (like chlorantraniliprole, fipronil and imidacloprid) may kill the subterranean termites in the garden while the repellent termiticides (such as bifenthrin and other pyrethroids) will usually just drive them away from the poisoned soil, leaving the colonies intact.

In any case, you'll still need to have a proper inspection done (in most areas that means not less than once a year) to have a good chance of finding any incursion before serious damage can happen.

The process of baiting for termites is highly variable. Sometimes termites take a weeks or months to go into a bait. Sometimes they're in by day two.

Some slow bait toxins may take months to noticeably affect the colony. This is especially true of the hormonal approaches which interfere with moulting. Some toxins will usually kill off a colony within two to three weeks of the first feeding. Three to eighteen months is about right for nearly all jobs and most are done by eight months..

Some termite species are bait shy and may take weeks or months to return to a disturbed bait. Some termite species don't share very well, so with them the toxin takes much longer to reach all parts of the colony.

If you are using a commercial bait system, the supplied information should be able to tell you roughly how long things should take. If you don't know, ask. The technician's job is to (i) manage the termites and (ii) communicate the process steps. You should always know how the technician is expected to declare when the termites are 'controlled'.

In some risk situations, baiting may become a permanent process. While DIY baiting is possible and widely promoted by bait sellers, it is rarely advisable to take on the whole job yourself. At least have a competent person assess the situation and detail the species and risks before you decide what to do.

Don't assume that because a lot of termites have been killed there won't be other (colonies) ready to move in an take up the attack. Even if you have baits in place, sometimes termites may not find them before beginning an attack. Baits are not anecessarily a reliable prophylactic measure.

After any baiting program, an ongoing inspection program is necessary.

The bottom line is that baiting may kill colonies but it is just part of your ongoing termite risk management and so doesn't really have an end date.

Termites will put a lot of effort into breaking through something that stands between them and the food or water they desire. Just so long as the prize justifies the effort required, they will appear as if to move mountains. Plaster (drywall etc.) is no barrier to termites. Most mortars slow them down, but lime mortars are readily penetrable. Termites will not usually do any damage to quality mortars with a high cement content, but beware of gaps and shrinkage cracks. Good quality concrete cannot be excavated by termites BUT cracks in poor concrete may be opened with ease. Autoclaved aerated concrete (those lightweight bubbly blocks) were readily penetrated in my field tests. Concrete (cinder) blocks sometimes have gaps in them big enough to interest termites (also observed in my field trials). Masonry is often built with lots of continuous gaps that termites can simply walk through, especially with extruded, hollow-core bricks.

Mud-brick (adobe) can be penetrated but there is most risk between the blocks and at cracks, penetrations and against timber framing.

In general, termites won't damage concrete if they can't pull out the sand (and small aggregate) particles. If the cement has been properly proportioned and the mix allowed to cure, then the particles tend to be well bound and termites are adequately deterred.

Termites can walk through cracks in concrete. The cracks need to be uniformly about 10% wider than the termites' head. Concrete that is properly placed, cured and is reinforced ('rebar') generally won't crack wide enough to be at risk. A properly designed and constructed concrete slab can be a building's main defence against subterranean termites.

Sometimes concrete has big pockets of air (because it was not properly settled), has wooden levelling pegs left in (termite highways) or has been damaged by expanding bolts or following trades cutting to add services. Easy termite paths are commonly found where floor slabs have cut-outs for baths or showers or where there are pipes or conduits passing through from the ground.

The technician will assess the activity in the baits over the course of the program and, usually, make a judgement call as to when success has been achieved (the subterranean termites killed). A good tech will almost never tell you that the termites are all gone but will talk about colony elimination or control or the length of time since any of the bait has been eaten. You'll still need ongoing inspections as baiting provides no residual control. Often colony decline can be observed to be happening when the proportion of soldiers increases or when the feeding workers develop white abdomens (uric acid crystals).

Baiting is used for subterranean termites (not drywoods and rarely for dampwoods). Baits use slow-acting toxins in low doses. The big problem is that there may be more than one colony active in the area Some colonies have fuzzy boundaries so that outside termites may be recruited to replace those affected. A great example of this is from Devon, England where introduced termites turned up in two houses. More than a decade of baiting later, there were still some termites active.

Don't Panic

Termite swarmers inside your home or bedroom may be very scary, but with luck, the risk can be assessed fairly quickly.Firstly, put down that can of fly spray. It really won't help and may make things a deal worse later on. Grab a few termites and put them in a plastic bag or a jar in the freezer. You may want these later for identification. Gather up the rest (vacuum or broom). Maybe feed them to your chickens or fish (if you didn't spray).

Now for the important bits.

Were the termites coming in from outside (this often happens if you leave a window open or have an outside light left on)? Termites outside are often just an unavoidable local hazard. Walk around to see if you can see them spilling out of any trees, garden wood etc.. Chances are it is just a few stragglers from a normal local flight. Order a specialist termite inspection if you haven't had one for a year (or if they were emerging from important timbers like pergolas, fences or out from your house).

Were the termites coming from inside the house? Sometimes they'll emerge right out of a wall, through the plaster, often near the top of a window or from a door frame or other feature. Look for little holes, often lined with brown or red mud and with termites dropping out or termite heads sticking out. If you have any of these signs, then you do have serious problems. Termites flying from within a house mean that there is a significant termite presence already having fun at your expense. Take some photos. Clean up the mess. Save your sample termites from the kids (or spouse) so that you can get them identified. Get a competent termite inspection. The termites may fly several times over the space of a few weeks.

Don't be rushed into any control measures. Consider your situation closely and act accordingly. Though it is true that the building may eventually fall down if you do nothing, this is usually years after the first flights and even then it tends to happen during storms.

Ants kill a lot of termites. Right around the world, and for most termite species, ants are the main predators. When you see termite soldiers, most of the funny-shaped jaws or pointy or blocky heads are really there as effective adaptations against attacking ants. When termites fly, lots get eaten before they can create a safe nest. This makes life very hard for termites, but usually not so hard as to kill them all off.

The battles between ants and termites have been raging for millions of years, with no clear winner. It's good to have ants around your home as these make things harder for termites, especially those just starting new colonies but because termites are good at surviving ant attacks, the mere presence of lots of ants is no guarantee that you won't get termites. Ants are useful, but not reliable, predators of termites.

Should we demolish part of the house that's got termites in it?

First up, the answer depends on what type of termites are creating the problem. If they are drywood termites, then maybe knocking things down will kill them, but if these are subterranean termites then definitely not. Drywood termites live in small colonies, usually in individual pieces of timber, so a thoughtful demolition may effectively remove active colonies. Subterraneans don't; they like to spread out through the structure and will have several paths to ground (for water). At the first strong vibrations, they will just go to ground and come back up later to resume the attack, perhaps even somewhere a bit further away. Early repairs just makes them harder to control and may cost you a lot more money. Once you open up their workings, the fresh, drying, air will force the termites to retreat.

With all types of termite, the individual does not matter. You can kill about half the termites in a colony and have it recover. You have to destroy the colony itself. This is often best done with baits, dusts or non-repellent soil poisons. It takes time. At least a month, maybe several months to more than a year.

To be certain of the right course of action, you need a specialist termite inspection report and that means a competent inspection of the whole site by someone who really knows what they're doing, has the right tools, and uses them. Once you know the which, where and the why, you are ready to make a good decision. But in general, it is almost always best to control the colonies before you undertake and repairs or major changes unless the damage is a safety or security hazard.

What's a termite lifespan?

There's no simple answer to this one. It depends. The species, life-type, wear and tear, the colony's health--all these things affect the potential for a termite's long life. A worker or soldier termite can live to about three years in my lab, but most probably only live a year or so in the wild. They can also get killed soon after starting work and so, on average, many only last a few months. A reproductive female, the termite queen is something quite different. In some mound-building species queens are reported to last more than 40 years, perhaps several decades more! The reproducing males also last a long time (pdf). This would likely make them the longest-living insects.

As usual, though, termite reality is stranger than we first thought. Imagine an amoeba, a superbly simple single-celled animal. If one splits (binary fission), producing two individuals, is the original one alive or dead? I think it is still alive. Do we think the same if the animal is multicellular and reproduces less simply? The issue arises with termites. Japanese and American researchers looking at the DNA of countless individual termites in a large number of colonies have shown that the some termites of the genus Reticulitermes, have queens that can reproduce themselves parthenogenetically (without using male input ~ see this pdf). Almost a self-clone. So the queen's genes go marching on. Oddly, their research shows the male genes in the colony to be fairly constant, meaning that they have also likely discovered that kings (male reproductives) individually last longer than females.

'Drywood' is a misnomer. Absolutely all types of termites do need some water to live and none can survive for long in totally dry wood. The drywood termites though, are very good at getting by with surprisingly little moisture and this enables them to live in small colonies in small pieces of just-damp wood. They can thrive, while the wood is good food that stays sufficiently moist and doesn't get too hot or too cold. Mostly drywood termites are found in the tropics, in forests and along coasts and rivers. In fact, anywhere that regularly has enough water in the air so that wood tends to always stay that bit moist.

Most mature drywood termite colonies number less than 1,000 termites and it may take the colony the best part of a decade to get to that size. Countering this, their habit of living within a piece of wood means that a house, tree, boat or even a door can be home to many separate colonies.

Drywood termites are cryptic. They don't tunnel in the soil, they don't build shelter tubes, they don't build mounds or other fancy structures which means that drywood termites can be quite hard to find (check the wording on your timber pest inspection--they may be excluded)-- see this pdf). Each colony tends to make one or more holes in the surface of their nest wood. They use these as waste chutes for faeces, blocking them up after use. Drywood termite poo is little hard pellets because they generally need to retain as much water as possible. Often a pile of pellets is a sure sign. I first noticed it as a gentle rain of pepper-like material falling from the roof frame of a rustic hotel restaurant in Carita, West Java. Even sitting 4 metres below the roof, I knew for sure they were there.

Normal termite controls (aimed at subterranean termites) are no use against drywoods. Using baits seems just plain silly. In small timbers (like doors, furniture, wooden legs etc.) it is easy to control the colony. In buildings it is often better to fumigate or 'treat' the whole structure, since you can rarely be 100% sure of finding and killing each individual colony.

The drywood termites are all placed in the Family Kalotermitidae. The main one around the world is the supertramp West Indian Drywood Termite, Cryptotermes brevis but there are tens of others that regularly worry people. Sometimes some of the dampwood termites (Termopsidae) act as if they were drywood termites, producing faecal pellets instead of wet poo, so they may be thought of as functionally or opportunistically drywood.

PS. Where I had used orange oil and wiped the excess from surfaces, a year or so later there is staining. Might just be the ones I was using, but be sure to fully clean away any residues.

Orange oil is the name given to extracts from the peel of citrus. Mostly this is near pure d-limonene. It is a general solvent. You have probably used it in bathroom or hand cleaner products that have a citrus smell. It kills insects. I specified it as the recommended cleanup solvent for the Blockaid non-toxic termite barrier as it was much less of an OH&S risk than mineral turpentine and is even known to potentially reduce some cancers.

In the USA it is being used as an injectable treatment against drywood termites, mostly in California as heavily promoted by a bloke who writes for the usually high quality SFGate. In 2007 the Californian Structural Pest Control Board commissioned research on the spot treatment of drywood termites and has available, for free download, excellent reports of the work headed by Drs Vernard Lewis and Mike Rust. If you must do spot treatments for drywoods, then read these reports! An in-depth and not very complimentary review of the orange oil method is available online at http://www.birc.org/JanFeb2008.pdf

So long as you can get it to soak through the at-risk timber, a good dose of limonene should kill the termites but as for any residue providing long-term deterrence, well don't hold your breath because it evaporates. You'd probably need to seal the holes and put a quality coating system over it (filler and paint or varnish) to get any to stick around. If the timber is more than slightly damaged, replacement may be advisable.

I've also had great success using d-limonene as a fire starter. A small amount will help even the stubborn logs light. Makes a lot of smoke (good for lighting Hawaiian bbq?). So, while I'm sure the chemical can kill termites, beetles, ants and maybe even some fungi, I'd hesitate to use it myself anywhere that there was a risk of fire but perhaps that's because I live in a high fire risk zone

The usual proviso with drywoods also applies, depending on your situation. You may never find all the colonies, so fumigating the whole structure may be a safer alternative to spot treatments.

Very few termites are likely to be interested in eating the straw bales themselves. Even those that normally eat grass. Lots of subterranean termites will happily travel through the bales to reach unprotected framing timbers (such as door frames and window lintels - see photo).

You won't sit the bales right on the soil anyway (moisture hazard) so all it takes is some attention to design to put a subterranean termite block in the foundation, just as you would with any other house design.

If you've already built without considering, find a well-skilled termite manager to inspect and advise. Keep in mind that the biggest threat to straw bales (after moisture-caused decay) comes from rodents, especially mice.

Generally not. You want your firewood dry (so that it burns well). If you cut it, split it and put it outside and up off the ground out of the rain, then it will dry quickly and any termites in it will slowly die. Ants and other predators will help. The only way this doesn't work is if you are in a humid area with a drywood termite risk. Drywoods may persist for a long time as the wood slowly dries. If you do find termites, don't do silly things like this guy who caused a major fire. Cut early, well before the cold weather, and let the sun and the air do the work for you. Unless the wood contains a nest, only a few of the major pest species can rebuild a colony from the workers and soldiers feeding in the wood.

Young children (and the unborn) tend to be at higher risk from environmental toxins that are adults. The risk you will face depends on both the type of termite and the type of treatment. that's being done. Basically there are three types of treatment.

The lowest risk are with baits for subterranean termites which use hormone-like chemicals to interrupt insect growth. At the rates they are applied, these are very low risk to people (and anything else that hasn't got its skeleton on the outside).

Next are the fumigant gases uses when a building is tented for drywood termites, these evaporate away almost entirely and pose little if any risk to you (or any returning termites) if the gas is properly handled and vented. Make sure that everything has enough time to out-gas. Some furnishing (like rubber cushions) may need a longer time.  Your technician will advise.

Last are the straight poisons (termiticides) which are usually applied to the soil but are increasingly used indoors as well. These always pose some risk, especially if poorly applied. You need to find out the identity of the toxin and look it up on the next. Search on 'toxicity of" and then the chemical name (not just the product name). Termiticides are not all the same, and  some termiticides are best avoided because of their risk profiles (such as organophosphates and still in some countries, organochlorines).  Nearly all will persist for quite some time, and this is where exposure is likely. Make sure you are away when the chemical is placed and don't return until after the recommended period. You will need to do your own research, but from manufacturer claims, it looks like the current least-toxic soil termiticide is chlorantraniliprole, closely followed by imidacloprid. Many will dispute this. The biggest risk is chemicals sprayed on the soil around the building where your child plays and will inevitably pick up and ingest some (kids eat a lot of soil). Sometimes, chemicals are applied as dusts or foams into wood or wall cavities. As long as any excess is cleaned up (and you don't open the cavity), the risks are considered low.  In a few backward countries, like Australia, the government allows for arsenic dust to be used. Arsenic dust is highly toxic, doesn't break down and isn't not more effective than the modern alternatives. It should never be used. If you find unexplained red, blue or white dust in termite-eaten wood or their old shelter tubes, please consider it dangerous until proven otherwise.

Sorry, but you've probably done the wrong thing. These tubes are produced by subterranean termites and provide cover for them to traverse over things they don't want to eat in order to reach the things they do want to eat. If upset by the disturbance, the termites can easily switch to another path into the house--often one that you can't find. Trouble is, you termite inspector may not be able to find it either. It is almost always better not to disturb them until you have a proper inspection done and decided on the right response strategy. Instead of slowing them down, you have likely slowed yourself and the likely result is that it may end up costing you a bit more to be rid of them.  Sometimes the termites will quickly repair a damaged tube but some species will stay away for a long time and a few may not ever come back.

One thing that's sure is that breaking their tubes is not a safe way to control the colony. On the other hand, if your house sits up on stilts or stumps, then having a few trained chickens underneath to regularly break the tubes may actually give good control (used in some Pacific islands) but only if the termites have no alternative concealed entry paths.

You can do it right now, but should keep your garden far from the house. Something over 6 feet or 2 metres is good. The water you add to the soil will be attractive to termites, so the further out the better (but not so far you can't nip out for a herb). If this doesn't work for you, grow your garden in raised tubs that you can see underneath.

Make sure that you don't dig up the termtiicide-soaked soil. If you dilute, damage or remove the volume of poisoned soil, you may enable termites to enter.  This is a bigger risk if your termiticide was a repellent one, like Bifenthrin, as the trmites can easily detect where there are gaps.
Leafy greens will often take up toxins from the soil and some termiticide sprays (like imidacloprid) are taken up by plants. That's good if you have aphids, but but maybe not so much if you have termites.
Most perimeter sprays aren't much good after 5 years, but it is still best to leave them until your regular inspector says you need more work done.

In some parts of the world, particularly parts of Africa and Asia, termites will quickly attack and kill transplanted trees and plants.  They attack the roots.  In the past, some very heavy doses of scary pesticides have been used to help the plants get established.  The attacks seem to drop off once the plants have been in for a few months. Keeping the plants well-watered all the time can make a big difference as water-stressed plants are more readily attacked. If you do decide to use a termiticide at planting, make sure the product label covers this application. Opinion as to whether to use a repellent or non-repellent termticide seems to vary with locations and species and some find value in a systemic (such as imidacloprid) that makes the whole of the plant toxic for a while (even the pollen, so don't use on plants that are close to flowering).

Should I get the house sprayed?