Eastern subterranean termites swarm in Virginia from March through June, most heavily in spring, on warm days following rain when temperatures climb above about 60°F. A swarm is not the beginning of an infestation — colonies produce winged reproductives only after several years of establishment. Seeing one indoors means the colony is in or under the building.
This page describes a seasonal event. If you have found wings and want to identify them, start with wings on a windowsill.
This is general information. Identification and extent can only be established by a licensed inspector at the property.
The conditions that trigger it
Swarming is weather-driven rather than calendar-driven, which is why the same house can swarm in mid-March one year and late April the next.
Temperature above roughly 60°F. Warm days, not warm afternoons after a cold night.
Following rain, or during high humidity. The classic trigger is a warm day after a spring rain.
Daytime for the eastern subterranean termite. This species typically swarms during daylight hours, which is one distinguishing feature — some other species swarm at dusk or at night.
Once mature. Colonies do not swarm until they can support reproductives, which generally means several years.
What a swarm is actually doing
Winged reproductives — alates — leave the colony to mate and to found new colonies. After the flight they shed their wings, which is why you find loose wings rather than insects.
Most fail. The biological purpose is dispersal at scale, and the survival rate for individual pairs is low.
What matters to you is not the swarmers. They are the visible fraction of a colony that is otherwise entirely hidden, and they do no damage themselves. The workers, which you will not see, are what consume the structure.
Inside versus outside: the distinction that matters
Swarmers emerging inside the structure — from a wall, a window frame, a ceiling, a crack in a slab — indicate a colony in or under the building. This is the finding that changes your situation.
Swarmers outside on a warm spring day may have come from anywhere within flight range: a neighbouring property, a tree stump, landscape timbers, a woodpile. It is a reason to inspect, not by itself proof of an infestation in your house.
If you did not see them emerge, the wings alone will not tell you which happened — but where you found them helps, and an inspector can often say more from the location than you can.
The spring calendar, roughly
| Period | What is typical |
|---|---|
| Early March | first swarms in warmer parts of the state, weather permitting |
| March–April | peak activity for eastern subterranean termites |
| May–June | continuing swarms, tapering |
| September–November | drywood termite swarms in coastal areas, where present |
Regional variation within Virginia is real. Tidewater warms earlier than the mountains, and elevation shifts the timing by weeks.
Why this is the season people find termites
Not because termites are seasonal — the colony feeds year-round — but because this is the only time of year they make themselves visible.
That produces a predictable pattern: a spike in discoveries every spring, and a corresponding spike in demand for inspections and treatment. Two practical consequences follow.
Scheduling gets tighter in spring. If your discovery collides with a settlement date, the queue matters.
Quotes deserve more scrutiny in season. High demand is when pressure selling appears. A swarm requires an inspection; it does not require a decision that afternoon.
What to do when you see one
Do not spray. Swarmers die shortly anyway, and the colony that produced them is elsewhere. Spraying destroys evidence and accomplishes nothing.
Collect a sample. A few wings in a sealed bag or between two pieces of clear tape. This is the single most useful thing you can hand an inspector.
Photograph the location before cleaning, with something for scale.
Note whether they emerged indoors, and from exactly where. Write it down while it is fresh.
Then look for the rest: mud tubes on foundation walls and piers, wood that sounds hollow, bubbling paint, stiff windows and doors.
Book an inspection. In season this may not be same-week.
What this means for you specifically
If you own and live in the home
Nothing must happen today, but the season is when access to inspectors is worst, so waiting has a cost of its own.
Your action: book the inspection now and keep the wings. Ask specifically whether the swarmers appear to have emerged from inside the structure.
If you are selling this spring
Swarm season and the spring selling season are the same season. That is not a coincidence problem — it is a scheduling one.
The standard Northern Virginia contract requires a report dated no more than 90 days before settlement, and puts treatment and repair of identified damage on the seller with written evidence before settlement.
Your action: get the inspection done early in the contract period. In spring, both inspectors and repair contractors are busiest. The contract clause →
If you are buying this spring
A property inspected in March may show what a property inspected in November would not.
Your action: ask whether the inspection occurred during swarm season, and read the section of the report listing what could not be accessed. Reading the report →
If you rent
The structure is the landlord's responsibility through the habitability duty; your duty is prompt written notice.
Your action: report in writing today with photographs, and keep the wings. Step by step →
Before you call: what costs what
An inspection and a treatment are two separate services with separate prices, and conflating them is the most common way people end up surprised by a bill.
| Typical Virginia range | What it produces | |
|---|---|---|
| Wood-destroying insect inspection and report | $65–$200 | the NPMA-33 form |
| General pest inspection | often free where the company expects to quote treatment | a verbal or written assessment |
| Termite treatment | $500–$2,000; more where damage is extensive | a treatment record |
| Structural repair | quoted by a contractor, frequently the largest of the three | an invoice, not a pest control document |
What is usually free: a quote for treatment, once a company has seen the problem.
What is usually not: the inspection report used in a real estate transaction, and any visit that produces a document rather than a price.
Ask which applies before you book. A company quoting one figure covering both inspection and treatment is not quoting what a sales contract or a lender requires.
Common misunderstandings
"They arrived this spring." Swarming requires a mature colony — several years of establishment.
"It's just the season, everyone gets them." Swarms are seasonal; a swarm emerging inside your walls is not a general spring phenomenon.
"I killed them all." The swarmers are a tiny visible fraction. The workers are what matter.
"No swarm this year, so they're gone." Swarming depends on weather and colony maturity. Absence is not evidence.
"They only swarm in spring." Eastern subterranean termites, largely yes. Drywood termites in coastal areas swarm in autumn.
"Flying ants swarm too, so it might be nothing." True, and it takes seconds to tell them apart. How →
What to ask an inspector
- Can you tell whether these emerged from inside the structure?
- Which species, and what supports that?
- Given the season, how soon can you actually get here?
- What could you not access on this property?
- Is treatment urgent this week, or is this a decision I can take properly?
- What is the cost, quoted separately for inspection and treatment?
- Under what name is your Virginia pesticide business license held?
The fifth question is worth asking plainly in spring. An honest answer is usually that a colony of several years' standing will not become materially worse while you get a second quote.
What to have ready
Property address and year built, foundation type, where you found the wings and on which floor, the date, whether you witnessed the emergence and from where, prior treatment history or an existing bond, and your settlement date if you are under contract.
Frequently asked questions
Exactly when do they swarm? March through June for eastern subterranean termites in Virginia, peaking in spring, on warm days after rain.
Do they swarm at night? Eastern subterranean termites typically swarm during daylight. Some other species swarm at dusk or after dark.
Will they swarm again next year? If the colony persists, yes. Recurrence is a strong indication that whatever was done has not resolved it.
Does a swarm mean the damage is severe? It means the colony is mature. Extent of damage is a separate question, answered by inspection.
Should I turn off outside lights? Swarmers are drawn to light, and reducing exterior lighting during a swarm reduces how many come to your doors and windows. It does nothing about the colony.
Verify before you pay anyone
VDACS maintains a public pesticide search at pesticidesearch.vdacs.virginia.gov and publishes an updated list of licensed pesticide businesses weekly. Wood-destroying pest control is category 7b under 2VAC5-685-70.
Ask which name the license is held under. How to check →