Subterranean Termite Swarming

Subterranean Termite Swarms: What Homeowners Should Know

Seeing hundreds of winged insects suddenly appear around your property can be alarming. In Southern California, a swarm may consist of subterranean termites leaving a mature underground colony to reproduce and establish new colonies.

A swarm near your home does not automatically mean the structure is infested. However, termites emerging from inside the building should be investigated promptly.

Why Do Subterranean Termites Swarm?

Subterranean termites live in colonies in the soil. When a colony reaches maturity, it may produce winged reproductive termites called swarmers or alates.

The swarmers leave the colony, fly a relatively short distance, and attempt to pair with mates. After landing, they shed their wings and look for a suitable place to begin a new colony.

Most swarmers do not survive or successfully establish colonies. Nevertheless, a swarm shows that a mature termite colony is somewhere in the surrounding area.

When Do Subterranean Termites Swarm in Southern California?

Swarming time depends on the termite species, temperature, rainfall, and location.

Common subterranean termites in California frequently swarm during the daytime in spring or fall. Warm, clear weather following soaking rain can trigger a large swarm.

Therefore, subterranean termite swarming should not be limited to a single February-to-May season. Swarms may occur at other times when environmental conditions are favorable.

Drywood termites commonly swarm during summer and fall, so the time of year can help with identification—but timing alone is not enough to determine the termite species.

How to Identify Subterranean Termite Swarmers

Termite swarmers are commonly mistaken for flying ants.

Winged termites generally have:

• Straight or beadlike antennae
• Broad waists
• Four wings of approximately equal length
• Wings that extend beyond the body

Winged ants generally have:

• Elbowed antennae
• Narrow or pinched waists
• Front wings that are longer than their rear wings

After swarming, termites shed their wings. Small piles of matching wings near windows, doors, baseboards, or light fixtures can be an important clue.

Save several insects or wings in a sealed container when possible. A clear photograph may also help with identification.

Does an Outdoor Swarm Mean the House Has Termites?

Not necessarily.

Subterranean termite colonies may live beneath landscaping, tree stumps, fences, buried wood, or other cellulose materials in the soil. A swarm in the yard or neighborhood does not prove that termites are actively infesting your house.

An outdoor swarm does show that subterranean termites are present nearby. Inspect the foundation and other accessible areas for:

• Mud tubes
• Wood-to-soil contact
• Damaged or blistered wood
• Plumbing leaks
• Poor drainage
• Tree stumps or buried lumber near the building

Consider a professional inspection if termites swarm immediately next to the foundation, repeatedly appear around the property, or other evidence is present.

What Does an Indoor Swarm Mean?

Termites emerging indoors are more concerning than termites flying outside.

Swarmers appearing inside a bathroom, kitchen, garage, or another room may have entered from outdoors. However, a large number emerging through a wall, floor, baseboard, plumbing opening, or foundation crack can indicate a colony with access to the structure.

An inspection is normally necessary to determine where the termites originated and whether the building is infested.

What Should You Do During a Termite Swarm?

If termites appear inside your home:

1. Photograph where they are emerging.
2. Save several specimens for identification.
3. Note the date, time, weather, and exact location.
4. Avoid spraying the insects or emergence point.
5. Do not seal the opening before it is inspected.
6. Vacuum the remaining insects after collecting a sample.
7. Arrange for a professional termite inspection.

The swarmers themselves cause little immediate damage. The more important question is whether an established colony is feeding on the structure.

Look for Subterranean Termite Mud Tubes

Subterranean termites commonly build shelter tubes from soil, saliva, and small pieces of material. These earth-colored tubes allow termites to travel between the soil and wood while maintaining a protected environment.

Mud tubes may be found along:

• Foundations
• Garage walls
• Crawl spaces
• Plumbing penetrations
• Interior walls
• Areas where wood is close to soil

Removing a visible tube does not eliminate the underground colony. Photograph its location before disturbing it.

How Are Subterranean Termites Treated?

Subterranean termite treatment is different from drywood termite treatment.

Depending on the property and inspection findings, treatment may involve:

• Trenching and treating soil near the foundation
• Drilling through concrete to reach the soil below
• Treating accessible shelter tubes or entry points
• Installing and monitoring termite bait stations
• Removing damaged wood
• Correcting moisture and wood-to-soil conditions

Whole-structure fumigation controls drywood termites inside a building, but it does not eliminate subterranean termite colonies living in the soil.

Treatment should be based on a professional inspection and correct identification of the termite species.

Subterranean Termite Inspections in Southern California

Tiger Termite Control provides subterranean termite inspections, treatment, and termite damage repairs throughout Chino Hills and surrounding Southern California communities.

If termites are swarming inside your home or you have found mud tubes or suspicious wood damage, call Tiger Termite Control at (909) 597-6953.

Free estimates are available when the property is not being sold or refinanced.

Updated September 2026.