California Ground Squirrel Control
The California ground squirrel (Otospermophilus beecheyi) is the most widespread and damaging ground squirrel species in Southern California. Colonial, disease-carrying, and capable of rapid population growth, California ground squirrels require professional pest control when they establish on residential or commercial properties. Rodent Guys provides chemical-free California ground squirrel control throughout Los Angeles, Orange, San Bernardino, and Riverside counties.
About the California Ground Squirrel
The California ground squirrel is a medium-sized rodent, 14-20 inches long including the tail, with mottled brown-gray fur and a bushy tail. It is active above ground during daylight hours — most active in morning and late afternoon — making it far more visible than gophers or moles. If you can see the animal scurrying across your yard, it is almost certainly a California ground squirrel.
California ground squirrels are colonial. A single property can support a colony of a dozen or more squirrels living in interconnected burrow systems. Burrow entrances are 3-4 inches in diameter and left open — unlike gopher tunnels, which are plugged with soil. Multiple entrances often dot a hillside or slope, connected by underground chambers that can extend 6 feet deep and 35 feet long.
California ground squirrels are year-round residents in Southern California. Unlike some ground squirrel species that hibernate, California ground squirrels remain active through most of the year, with only a partial summer torpor during the hottest months in inland areas.
Why California Ground Squirrel Control Is Urgent
Plague risk. The California ground squirrel is the primary reservoir of bubonic plague (Yersinia pestis) in Southern California. Plague-infected squirrel fleas can transmit the disease to humans and pets through bites. Plague cases in California are rare but real — the California Department of Public Health monitors ground squirrel populations for plague activity. Properties where children and pets spend time outdoors should address ground squirrel infestations as a health priority, not just a nuisance. See our guide on ground squirrel disease risks.
Structural damage. Ground squirrel burrow systems undermine foundations, retaining walls, slopes, and hardscape. On hillside properties common throughout the Inland Empire and foothills, extensive burrowing can destabilize slopes and lead to erosion. Irrigation lines and utility conduits buried near burrow systems are frequently damaged.
Plant and crop damage. California ground squirrels eat seeds, bulbs, nuts, fruit, and young plants. A colony can strip a vegetable garden or damage ornamental plantings rapidly. Properties with fruit trees, bird feeders, or vegetable gardens attract and sustain larger squirrel populations.
Colony growth. California ground squirrels breed once per year with litters of 5-8 pups. A small colony left untreated through a single breeding season can double or triple in size. Early treatment before breeding season (late winter to spring) is significantly more effective and less costly than addressing an established large colony.
California Ground Squirrel Control Methods
Trapping. Traps placed at active burrow entrances and along travel corridors are the most targeted California ground squirrel control method. Trapping is ideal for smaller infestations, properties near neighbors, and situations where minimizing collateral risk is the priority. Our technicians monitor traps daily and remove caught animals promptly to prevent attracting other wildlife.
Carbon monoxide treatment. Carbon monoxide injected into active burrow systems is highly efficient for established colonies. CO fills the interconnected tunnel network and reaches animals throughout the system in a single treatment. This method is faster than trapping for large colonies and leaves no surface residue. It is the preferred method for properties with extensive burrow systems or large squirrel populations.
Why we do not use rodenticide bait. Grain-based rodenticide is widely used for ground squirrel control, but it creates serious risks on residential properties. Bait stations can be accessed by dogs and cats. Poisoned squirrels that die above ground or near the surface cause secondary poisoning in hawks, owls, and foxes. On properties where children play, the risk of bait contact is real. Rodent Guys uses only trapping and carbon monoxide.
Where California Ground Squirrels Are Most Common
California ground squirrels are abundant throughout Southern California but are most problematic in specific settings:
Foothill communities. Cities bordering the San Gabriel, San Bernardino, San Jacinto, and Santa Ana mountains — Pasadena, Arcadia, Glendora, Upland, Rancho Cucamonga, Redlands, Corona, and dozens more — experience heavy ground squirrel pressure from adjacent hillsides and open space.
Properties near open space. Parks, golf courses, undeveloped parcels, and HOA common areas provide refuge populations that continuously repopulate adjacent residential yards. Properties within a quarter mile of significant open space almost always have ongoing squirrel pressure.
Horse properties and ranchettes. Grain storage, feed areas, and open pasture attract and sustain large ground squirrel populations. Burrow openings in pastures create serious ankle-injury hazards for horses.
New construction neighborhoods. Development displaces existing squirrel colonies into adjacent landscaped properties. New sod, irrigation, and fresh landscaping attract displaced squirrels rapidly.
Service Areas
Rodent Guys provides California ground squirrel control throughout Southern California. View our full service area list or call 909-599-4711 to confirm availability in your city.
Related Articles
- Are Ground Squirrels Dangerous? Disease Risks Explained
- Pest Control for Ground Squirrels
- Carbon Monoxide Treatment — How It Works
- Why Rodenticide Is Dangerous for Pets
- Secondary Poisoning in Hawks and Owls
- Gopher vs. Mole vs. Ground Squirrel — Identification
- Ground Squirrel Service Page
Frequently Asked Questions
The California ground squirrel (Otospermophilus beecheyi) is the most common ground squirrel species in Southern California. It is a colonial burrowing rodent active above ground during daylight hours and a known carrier of plague and other diseases.
The most effective methods are trapping and carbon monoxide treatment. Trapping targets individual animals at burrow entrances. Carbon monoxide addresses entire colonies efficiently. Rodent Guys uses both methods and does not use rodenticide bait.
Yes. California ground squirrels are a primary reservoir of plague in Southern California. Their fleas can transmit plague to humans and pets. They also carry typhus and other diseases.
No. California ground squirrels are classified as a pest species and may be controlled year-round. Specific rodenticide products are regulated and require a licensed pest control applicator.
Call 909-599-4711 for California ground squirrel control anywhere in Southern California. Free estimates, chemical-free methods, no rodenticide bait.