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High RiskTermite Control in Ontario, CA
California-licensed termite inspectors serving Ontario and all of San Bernardino County. Free whole-structure inspections, honest treatment recommendations, and every method available — from orange oil to tent fumigation.
Ontario is one of the Inland Empire's oldest cities, and its historic downtown district contains 1890s–1930s homes with original framing that carries significant drywood risk. More broadly, the city's agricultural soil history — once part of the Ontario Model Colony irrigation system — left a legacy of high soil moisture that sustains above-average subterranean termite pressure across virtually all residential areas, including newer development built on former grove land.
Our Ontario Service Info
Service Area
Ontario, San Bernardino County, CA and surrounding areas
Inspection Fee
Free — no obligation
Peak Swarm Season
March, April, May (peak: April)
CA License
Structural Pest Control Board #PR7791
Phone
(714) 240-2800
Reviews
4.9★ rating from Southern California homeowners (Google verified)
Termite Risk in Ontario
Ontario is one of the Inland Empire's oldest cities, and its historic downtown district contains 1890s–1930s homes with original framing that carries significant drywood risk. More broadly, the city's agricultural soil history — once part of the Ontario Model Colony irrigation system — left a legacy of high soil moisture that sustains above-average subterranean termite pressure across virtually all residential areas, including newer development built on former grove land.
Warm Climate Year-Round
Ontario's mild temperatures allow termite colonies to remain active throughout the year — unlike colder climates where activity slows in winter. There is no "off season" for termites in Inland Empire.
Aging Wood Structures
Many homes in Ontario were built in the 1950s–1980s. Older wood framing, fascia, and eaves are more susceptible to drywood termite infestation, especially if paint or sealant has deteriorated.
Coastal Humidity
Moisture from coastal air and irrigation creates ideal conditions for subterranean termites, which require soil moisture to thrive. Foundation areas, crawlspaces, and soil-to-wood contact points are especially vulnerable.
Dense Housing
In densely-developed areas like Ontario, termite swarmers from neighboring properties can easily establish new colonies in your home. A neighbor's treatment can even push colonies into adjacent structures.
Inspector Note — Ontario
“Historic Ontario homes near Euclid Avenue often have original citrus-era irrigation channels converted to drainage beneath the property — these channels maintain chronic soil moisture and require special attention during the subterranean assessment.”
Signs of Termites in Your Ontario Home
Termites rarely announce themselves. These are the warning signs Ontario homeowners most commonly miss until the damage is already significant.
Frass / Droppings
Small hexagonal pellets that resemble sawdust or coffee grounds appearing below eaves, window frames, or baseboards. This is drywood termite waste and a definitive sign of active infestation.
Kickout Holes
Tiny round holes (about 1mm) in wood surfaces — typically in eaves, fascia, or door frames — where drywood termites push frass out of their galleries.
Hollow-Sounding Wood
Tapping on structural wood that sounds hollow or papery indicates termites have consumed the interior while leaving a thin outer shell. Common in attic beams, window sills, and floor joists.
Mud Tubes
Pencil-width tunnels of mud and debris running along foundation walls, pipes, or exterior surfaces. These are the travel highways of subterranean termites, built to maintain moisture as they move from soil to wood.
Swarmers / Flying Termites
Winged termites (alates) emerging from walls or flying near windows are a strong sign a mature colony is nearby. They shed their wings quickly — discarded wings on windowsills are a common clue.
Blistering Paint
Paint that bubbles, blisters, or peels from the inside out — without an obvious water source — can indicate subterranean termites tunneling through wall framing, introducing moisture as they work.
Termite Treatments Available in Ontario
We offer every proven treatment method. After a free inspection, our licensed inspector recommends the right approach for your specific infestation and home type.
Tent Fumigation
The most thorough drywood termite treatment. The entire structure is tented and fumigated with Vikane gas, eliminating all drywood termites throughout the home. Required for severe or whole-house infestations.
Tent fumigation details →Orange Oil Treatment
A no-tent alternative using d-limonene (orange oil) injected directly into termite galleries. Effective for localized drywood infestations. No need to leave home. Eco-friendly and low-odor.
Orange oil treatment details →Heat Treatment
The structure or specific areas are heated to 130°F+, killing all termites and eggs without chemicals. Effective for drywood termites and can treat the whole structure without tenting.
Heat treatment details →Termidor / Liquid Treatment
A perimeter soil treatment using Termidor (fipronil) that creates a protective zone around the foundation. Highly effective for subterranean termites. Long-lasting and transfers through the colony.
Termidor liquid barrier details →We offer 8 treatment methods in total. View all treatment options
Termite Services in Ontario
Explore detailed information about each treatment method specific to Ontario homes.
Tent Fumigation
$1,500–$4,000
Whole-structure drywood termite elimination using Vikane gas
Tent Fumigation in OntarioOrange Oil Treatment
$500–$1,500
No-tent drywood termite treatment using natural d-limonene
Orange Oil Treatment in OntarioHeat Treatment
$1,200–$3,000
Chemical-free termite elimination using thermal heat
Heat Treatment in OntarioTermite Inspection
Free
Free whole-structure termite and WDO inspection
Termite Inspection in OntarioSubterranean Termite Treatment
$800–$2,500
Termidor liquid barrier for subterranean termite elimination
Subterranean Termite Treatment in OntarioDrywood Termite Treatment
$300–$1,500
Targeted drywood termite elimination using spot treatment or orange oil
Drywood Termite Treatment in OntarioTermite Damage Repair
$200–$8,000+
Licensed repair of termite-damaged wood and structural members
Termite Damage Repair in OntarioReal Estate Termite Inspection
$295 flat fee
Section 1 & 2 WDO reports for escrow, VA/FHA loans, and real estate transactions
Real Estate Termite Inspection in OntarioWhy Ontario Homeowners Choose Ultimate Termite
Not all termite companies are the same. Here's how we compare to national chains.
| Factor | Ultimate Termite | Orkin / Terminix / Western |
|---|---|---|
| Specialty | Termites only — it's all we do | General pest control with termite add-on |
| Inspector | CA-licensed structural pest inspector | General technician |
| CA License | #PR7791 — Structural Pest Control Board | Various (may vary by technician) |
| Free Inspection | Yes — full whole-structure inspection | Yes, but sales-focused |
| Treatment Options | All 8 methods available | Limited options (usually 2–3) |
| Local | Orange County, CA — locally owned | National corporations |
Serving Ontario and Nearby Areas
Our licensed inspectors serve Ontario and the surrounding communities throughout San Bernardino County, including Rancho Cucamonga, Upland, Fontana, and Montclair. Whether you're in the heart of Ontario or on the outskirts, we can schedule a free inspection promptly.
We cover all of Inland Empire — Orange County, Los Angeles County, the Inland Empire, and Riverside County. View the full San Bernardino County service area.
View Ontario's risk level on our interactive termite risk map →
Serving Ontario and Nearby Communities
Frequently Asked Questions — Ontario Termite Control
How much does termite control cost in Ontario?
Termite treatment costs in Ontario vary by method: spot treatment $300–$800, orange oil $500–$1,500, heat treatment $1,200–$3,000, tent fumigation $1,500–$4,000. We provide free no-obligation inspections before recommending any treatment.
Do you offer free termite inspections in Ontario?
Yes — Ultimate Termite offers free, no-obligation whole-structure termite inspections throughout Ontario and San Bernardino County. Call (714) 240-2800 or schedule online.
How long does termite treatment take in Ontario?
Treatment time depends on the method: spot treatment and orange oil take 2–4 hours, heat treatment 6–8 hours, and tent fumigation requires 3 days out of the home. We schedule promptly for Ontario homeowners.
What type of termites are most common in Ontario?
Ontario homes face both drywood and subterranean termites. Drywood termites are more common in older wood structures; subterranean termites are found near soil contact points. Our inspectors identify the species before recommending treatment.
Is Ultimate Termite licensed to work in Ontario, CA?
Yes. Ultimate Termite holds California Structural Pest Control license #PR7791 and is fully insured to perform termite inspections and treatments throughout Ontario, San Bernardino County, and all of Inland Empire.
Ready to Protect Your Ontario Home?
Get your free termite inspection today. No obligation, no pressure — just expert advice from CA-licensed inspectors.