The termite life cycle, and what it explains about your house
Egg, nymph, caste. Understand the order a colony grows in and most of the advice on this site stops sounding arbitrary.
How does a termite colony actually grow?
An egg hatches into something that already looks like a small, pale termite. It moults repeatedly, growing a little each time, and along the way it develops into one of the castes the colony needs: a worker, a soldier or a reproductive. There is no grub and no pupa. Termites have incomplete metamorphosis, which is one of the ways they differ from ants, whose young are helpless white larvae that have to be carried about.
That single fact explains a surprising amount. There is no inert life stage tucked away somewhere waiting to emerge. Almost every individual in the colony is a working part of it, moving, feeding and being fed. It is also why the colony can change its own composition. If it loses soldiers or reproductives, individuals still developing can be steered towards filling the gap.
The castes, and what each one means for a house
Workers are the great majority: pale, soft-bodied and blind. They forage, build the mud tubes and galleries, tend the eggs, and feed every other caste mouth to mouth. They are also the only caste that eats your timber. All termite damage is worker damage.
Soldiers do one job, defence, and it comes at a cost. The head and mandibles that make them useful in a fight leave most of them unable to feed themselves, so workers feed them too. Soldiers also carry the features used to tell one genus from another, which is why an inspector wants them in the sample.
Reproductives come in more than one form, and this is the part most people have not heard. There is the founding pair: the king and queen that started the colony after a flight. There are the alates, the winged forms a mature colony releases to start new colonies elsewhere. And there are supplementary reproductives, which develop inside an established colony from individuals that were heading for another caste.
| Caste | What it does | Can it feed itself? | What it means for you |
|---|---|---|---|
| Worker | Forages, builds tubes and galleries, feeds the colony | Yes: and feeds everyone else | The caste that eats the timber, and the caste a colony-directed treatment relies on |
| Soldier | Defence only | Mostly no; fed by workers | Carries the features used to identify the genus. Worth collecting |
| Alate | Leaves to found a new colony | Briefly | Shed wings indoors mean a mature colony nearby, not a new problem starting |
| Supplementary reproductive | Lays eggs inside an established colony | Fed by workers | Why "kill the queen" is not a plan, and why splitting a colony can backfire |
The queen, and why she is not the whole story
A mature termite queen is physically remarkable. As her ovaries develop, her abdomen swells enormously (the term for it is physogastric) until she is effectively a stationary egg-laying organ. She cannot move herself, and workers feed, groom and clean her around the clock. Termite queens are among the longest-lived insects known, and a colony's founding pair can persist for many years.
The useful part, though, is what happens when she is gone. Because the colony can raise supplementary reproductives from individuals already inside it, the death of a queen does not necessarily end anything. A colony that loses its royal pair, or a portion of a colony that gets cut off from them, can produce replacements and carry on.
This is why "find the nest and kill the queen" is not the way termite management is actually approached in Australia. And it is certainly not something a householder can do with a spade and a bottle of spray.
Why a colony has to be mature before it swarms
Alates are expensive to produce and they contribute nothing to the colony that makes them. A colony only starts making them once it is well established, and that takes years rather than weeks.
This is the practical consequence people miss when they find a pile of shed wings on a windowsill in spring. It is not the sign of something that has just begun. It means a mature colony has been living somewhere within flying distance for a long time already. What the alates and the shed wings mean goes through that in detail.
The same logic runs the other way. A pair of alates that lands, sheds its wings and starts a colony under your back steps will not produce a swarm of its own for years. And will not produce noticeable damage for a while either. That is the window a regular inspection cycle exists to catch.
Why the life cycle is the reason baiting works — and spraying does not
Everything a worker eats gets shared. Workers feed soldiers, reproductives and the young by passing food mouth to mouth, a process called trophallaxis, and they do it constantly. A colony is therefore a single connected digestive system, and anything that enters through a foraging worker has a route to every individual in it.
That is exactly the mechanism a colony-directed treatment exploits. It is also the mechanism a supermarket spray destroys. Kill or repel the workers at the point where you found them and nothing gets carried home: the colony seals off that route, abandons it. And comes back into the building somewhere you are not looking. Nothing about the colony has changed except that you no longer know where it is.
The moulting matters too. Every individual has to shed its cuticle repeatedly to grow, and workers keep moulting throughout their lives. That gives the whole colony a shared biological process, and actives that interfere with it travel by the same sharing that moves food.
The details of which approach suits which situation belong to the licensed technician who assesses the property; barrier versus baiting sets out how the two families differ.
What to do with all this if you have found termites
Nothing, which is the hardest instruction on this site. Do not break the tube open, do not lift the board, do not spray. And do not go looking for the nest. The life cycle is the reason: the colony is a connected, self-repairing thing with more than one way of replacing its reproductives and more than one way into your house. Disturbing the part you found removes your only reliable information about it and leaves the rest untouched.
Photograph it, leave it in place, and book a timber pest inspection to AS 4349.3. Every termiticide and bait active used in this country is registered by the APVMA and applied by a licensed pest management technician. If you want to know what an inspector is going to look at, the fifteen-minute walk-around is the version you can do without touching anything.
Frequently asked questions
How long does a termite queen live?
Termite queens are among the longest-lived insects known, and a founding pair can persist for many years rather than a single season. She does not move about: as her ovaries develop her abdomen swells until she is effectively a stationary egg-laying organ, fed and groomed by workers.
Does the colony die if the queen dies?
Not reliably. An established colony can raise supplementary reproductives from individuals already inside it, so losing the royal pair does not necessarily end anything. A cut-off portion of a colony can do the same and carry on independently, which is one reason disturbing workings is counter-productive.
Do termites have larvae like ants do?
No, and this is one of the clearest differences between the two. Ants go through a helpless white larval stage and then a pupa. Termites hatch looking like miniature termites and moult their way up, developing into workers, soldiers or reproductives as the colony requires.
How big does a colony get before it swarms?
Producing winged alates is costly and a colony only does it once it is well established, which takes years rather than weeks. That is why shed wings on a windowsill point to a mature colony that has been in the area for a long time, not to something that has just started.
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.
- Department of Health, Victoria. Pest control — termites
- Australian Pesticides and Veterinary Medicines Authority. Registered agvet chemical products (PubCRIS)
- Standards Australia. Australian Standards (AS 3660 termite management, AS 4349.3 timber pest inspection)