Know the Signs of Rodent Infestation

Live rat sightings are a sure sign that an infestation is in progress, but may not occur until an infestation has become severe. Instead, be alert for the signs of rodent infestation. Addressing infestations early will save you time, money, and effort.

Preventing Rodent Infestations

Rats and mice will seek out environments where food, water and shelter are found. Preventing rodent problems depends on eliminating these attractants. To discourage rodents from infesting your property:

• Store food and animal feed products in containers with tight-fitting lids.
• Store garbage in metal containers with tight-fitting lids. Empty garbage receptacles frequently.
• Clean up dropped or spilled food and garbage promptly.
• Keep all vegetation trimmed away from roofs, walls, fences, poles, and trees.
• Reduce clutter in storage areas, and keep them tidy.
• Store building materials and lumber at least 18″ off the ground at least 12″ from walls or fences.
• Keep rodents out of structures by sealing all openings larger than a nickel.
• Weather strip exterior doors, and keep doors and windows tightly closed, especially after dark.

Read more about preventing rodent infestations.

Rodent Control

Trapping rodents is the best method of control. It should be done after rodent proofing is completed. Trapping is especially desirable in areas where rodenticides cannot be used, such as indoors or in outdoor areas frequented by pets or children.

Traps should be placed perpendicular to rodents’ usual path of travel, such as against the base of walls, alongside beams, on ledges, or on vertical pipes. Pre-bait traps without setting them for several nights to allow rodents to become accustomed to eating from the trap. Read more about setting rodent traps.

If you or your pest control operator chooses to use a rodenticide, note that these products are toxic to people and pets. Rodenticides MUST be used according to the manufacturer’s label precautions and instructions. Always use rodenticides in child-proof bait stations. Rodenticides should never be used indoors, or prior to completing rodent-proofing; poisoned rodents may enter structures and die inside walls or attics, creating an unpleasant and unsanitary situation.

Selecting a Pest Control Operator

If you find signs of rodent activity in or around your business, you will likely need to hire a professional pest control service. Verify company’s licensing is current. All pest control operators must be registered with the California State Structural Pest Control Board, and should be insured. You may also want to contact the Better Business Bureau or read reviews of the company’s work. 

Make sure both you and the company understand the problem and the control work proposed before the start of any work. Obtain in writing details of the control work and treatment schedule. Read the contract carefully. A contract for pest control should include a description of the problem, a detailed treatment plan, the length of service, a detailed price breakdown, and a description of any guarantees.

Learn more about how to select a pest control operator HERE.

How We Can Help

The District doesn’t provide pest control services to individual businesses, but can help with rodent inspections, recommendations for rodent exclusion and control, and coordinating neighborhood-wide rodent prevention efforts. To request services, call 650-344-8592 or make a service request online.

Page last reviewed: September 26, 2023