Are Termites Active in Winter? What New Hampshire Homeowners Should Know

Yes, termites can stay active in winter, even in New Hampshire. Eastern subterranean termites survive freezing weather by staying in protected soil, and they can continue feeding wherever conditions remain warm enough. That includes areas beneath heated basements and foundations.

So if you've found winged insects around a basement window in February, don't assume they can't be termites just because there's snow outside.

New Hampshire winters slow termite activity near the surface, but they don't necessarily stop what's happening beneath your home.

If you're concerned about possible termite activity, Anchor Pest Services can help you explore termite treatment options. First, though, it's important to identify what you've found.

What Happens to Termites in a New Hampshire Winter?

New Hampshire is home to the Eastern subterranean termite, the most common termite species in New England.

Unlike insects that spend much of their time exposed to the weather, subterranean termites live in colonies underground. Their workers need moisture to survive, so they travel through soil, protected tunnels, and wood rather than moving across dry, exposed surfaces.

As the ground freezes, activity near the surface slows. Termites can retreat into deeper soil where temperatures are less extreme.

But the soil beneath a heated house doesn't always freeze the same way as the surrounding yard.

Warmth from the building can create more favorable conditions around the foundation. If termites have access to wood in those areas, feeding may continue even during the coldest months.

That's why a New Hampshire winter doesn't automatically put a termite infestation on hold.

Why Heated Basements Can Keep Termites Active

Older New Hampshire homes can have several features that make termite activity difficult to spot.

Fieldstone foundations, concrete block walls, and wooden sill plates close to the soil may provide places for termites to enter. Finished basements can also conceal wooden framing against foundation walls, hiding damage until it becomes more noticeable.

Heat is another factor.

Areas near furnaces, water heaters, chimneys, and hot water pipes may stay warmer than the surrounding ground. When termites can reach those areas through protected soil or tunnels, they may remain active through winter.

Moisture Matters, Too

Termites need moisture, and basements often have plenty of it.

A leaking pipe, damp foundation wall, poorly drained sump pit, or persistent condensation can create conditions that favor termite activity.

A damp basement doesn't automatically mean you have termites. But moisture problems are worth fixing, particularly when wood is close to the foundation.

Crawlspaces deserve the same attention. Insulation and vapor barriers can make some areas difficult to inspect, while gaps or moisture problems may go unnoticed.

If your home has a crawlspace, our guide explains how to prevent termites around crawlspace insulation and vapor barriers.

Can Termites Swarm in Winter?

Yes. Although termite swarms in New England are most common from March through June, they can occasionally happen earlier.

A stretch of unusually warm winter weather may trigger swarming activity. In heated buildings, indoor swarms can also appear in late winter or early spring.

That means finding winged insects around a basement window in February isn't something to dismiss.

Why Do Termites Gather Around Windows?

Winged termites, called swarmers, leave established colonies to reproduce and start new colonies.

They're attracted to light, which is why homeowners sometimes find them around basement windows, glass doors, or other bright areas.

You might see dozens of insects one afternoon and none the next. Sometimes all that's left is a scattering of wings on the windowsill or floor.

The swarmers themselves aren't responsible for most termite damage. Worker termites are the ones feeding on wood.

But swarmers emerging inside a home can indicate that a mature colony is present in or beneath the structure.

Termite Swarmer or Winged Carpenter Ant?

Not every winged insect you find indoors is a termite.

Winged carpenter ants also appear in New Hampshire homes, and the two insects can look similar at first glance.

Both can be associated with wood damage, but they behave differently and require different treatment approaches.

Here's how to tell them apart.

These differences can be hard to see without a close-up photo or a magnifying glass.

Our guide to carpenter ants vs. termites explains what to look for. You can also read more about winged carpenter ants and why they sometimes show up indoors.

If you're unsure what you've found, save a sample rather than guessing.

Signs of Termite Activity You Can Check in Winter

You don't have to wait for spring to look for warning signs.

Some evidence of termite activity remains visible throughout the year, especially in basements, crawlspaces, and areas around the foundation.

Mud Tubes Along Foundation Walls

Subterranean termites build narrow tubes from soil and other materials to travel between their colony and a food source while staying protected from dry air.

These tubes may appear along foundation walls, support posts, or wooden sill plates.

They're often about the width of a pencil, although their size can vary.

If you find a suspicious tube, photograph it and leave it in place for inspection.

Shed Wings Near Windows

After swarming, termites shed their wings.

Small piles of similarly sized wings around basement windows, doors, or floors may mean swarmers have been present.

The wings alone won't tell you where the colony is, but they're worth investigating.

Hollow-Sounding or Damaged Wood

Termites can feed inside wood while leaving much of the outer surface intact.

Affected wood may sound hollow when tapped or feel unusually weak.

Unlike carpenter ants, subterranean termites don't typically leave piles of clean sawdust outside their galleries.

Wood damage can have several causes, so an inspection is the best way to determine whether insects are responsible.

Bubbling Paint or Soft Trim

Bubbling paint, damaged trim, or soft wood near the foundation may point to moisture problems, insect activity, or both.

These signs don't necessarily mean you have termites. But if you also notice mud tubes, shed wings, or other suspicious evidence, it's time to investigate.

What to Do if You Find Swarmers Indoors

Finding winged insects in your home during winter can be unsettling. Here's what to do.

1. Don't spray them right away.

Spraying the visible insects won't eliminate a colony hidden in the soil or structure. It can also make identification harder.

2. Save a sample or take clear photos.

Collect a few insects in a sealed bag or container if you can. Close-up photos showing their wings, antennae, and waist can also help with identification.

3. Note where they appeared.

Were they near a basement window, an exterior door, or a furnace? Did you find them in one room or several?

These details can help the inspector narrow down where to look.

4. Schedule an inspection.

A pest control professional can identify the insects, look for signs of activity, and recommend the next steps.

For more guidance, read what to check when termite swarmers appear indoors near windows.

Even if the insects disappear after a day or two, the underlying problem may still be there.

Should You Treat Termites in Winter?

You don't necessarily have to wait until spring.

Termite inspections can be performed in winter when the relevant areas are accessible. Treatment may also be possible, depending on the infestation, the property's conditions, and the method needed.

Frozen ground and snow can limit access around the foundation, which may affect certain treatments.

That's why the decision should start with an inspection.

If termites are active beneath a heated home, waiting for warmer weather could allow damage to continue.

A qualified technician can assess the situation and recommend whether treatment can proceed during winter or whether certain work needs to wait for better conditions.

Found Winged Insects Inside?

Don't wait until spring to find out what they are.

Call Anchor Pest Services at (603) 785-0118 or book a termite inspection.

We'll help you understand the next steps and discuss the available termite treatment options.

FAQs

How can I tell if termites are active in my house?

Look for mud tubes along foundation walls, shed wings near windows, damaged wood, or live insects. Some signs can remain after an infestation is no longer active, so they don't always tell you what's happening now. A professional inspection can help determine whether termites are present.

Should you treat for termites in the winter?

Treatment may be possible during winter, depending on the conditions and the method required. Frozen soil and limited exterior access can affect certain treatments. A pest control professional can inspect the property and recommend the appropriate approach.

What is the fastest way to get rid of termites?

The first step is to identify the termites and determine where they're active. Professional treatment is designed to address the infestation rather than just the insects you can see. Spraying swarmers or using household products won't reliably eliminate a hidden colony.

Do termites die in the winter?

No. Eastern subterranean termites survive New Hampshire winters by staying in protected soil and other areas where temperatures are less extreme. Their activity may slow outdoors, but they can continue feeding where conditions remain warm enough.

Are there termites in New Hampshire?

Yes. Eastern subterranean termites are found throughout New Hampshire and the rest of New England. They live primarily underground and can damage wooden structures when they gain access to a building.

Why are there winged bugs at my windows in February?

They could be termite swarmers or winged carpenter ants. Both can appear indoors during winter, particularly in heated buildings, and both may gather near windows because they're attracted to light. Save a sample or take a close-up photo so a pest control professional can identify them.

In New Hampshire, subterranean termite colonies can survive below the frozen surface, and warmth around a home's foundation may allow feeding to continue through winter.

If you've noticed winged insects, mud tubes, or suspicious wood damage, it's worth checking now rather than waiting for spring.

Call Anchor Pest Services at (603) 785-0118 or schedule a termite inspection.

We'll help you find out what's happening and what to do next.

Buying a home? Our New Hampshire WDI inspection guide explains what the report covers before closing.