What California's rodenticide rules mean for your quote
California has prohibited most uses of first- and second-generation anticoagulant rodenticides. UC IPM lists the affected actives as bromadiolone, brodifacoum, difethialone, diphacinone, chlorophacinone, and warfarin, and notes that bromethalin, cholecalciferol, and zinc phosphide remain available. The practical effect is that a California rodent job is a trapping and sealing job. That changes what a fair quote looks like. Expect a list of entry points and materials, a trapping schedule with return visits over two to four weeks, and possibly a permitted bait product in locked exterior stations where pressure is heavy. Expect more labor hours than a bait-based plan in another state would need. It also changes what to ask. Which product, if any, will you use, and why is it allowed at my address? How many trap checks are included? What happens if I still hear rats after the last visit? A provider in Los Angeles or San Jose who answers those precisely knows the rules. One who says they will just put out bait may not.
Which rodents will you meet in California homes?
Four species appear in California's state data. The roof rat is the coastal climber, nesting in palms, ivy, and attics from San Diego to San Francisco and traveling 300 feet or more for food by UC IPM's account. Chewed citrus and avocados on the ground are its signature. The Norway rat is the burrower, found at ground level in older urban blocks and along waterfronts. It digs under slabs and foundations and comes up through crawlspaces. The house mouse is in every city, using gaps of 1/4 inch, and it is the rodent most people meet in a Fresno garage or a San Jose pantry. The deer mouse is the rural and foothill rodent and the hantavirus carrier. California's four provisional 2025 cases are the reason any droppings in a closed cabin, barn, or shed should be treated with ventilation and bleach rather than a broom. Knowing which of the four you have decides whether the work is on the roofline, at the foundation, in the kitchen, or in the outbuilding.
What does the first visit from a California rodent control company look like?
Because bait is limited, the first visit should be mostly inspection. On a coastal home the technician walks the roofline looking at tile ends, vents, and the joint where roof meets wall, plus every palm frond or vine that touches the house. At ground level they check the garage door against UC IPM's 1/2-inch rat rule, weep screeds, and utility penetrations. Inside, the attic is the main stop: droppings on insulation, rub marks on rafters, chewed duct or wiring. In the garage they check stored boxes and the water heater closet. On a foothill property they look at outbuildings for deer mouse sign. Before they leave, ask for three things in writing: the entry points found with the sealing materials, the number of trap-check visits, and the name of any bait product they intend to use and its legal basis. In California, a quote without a sealing list is a quote for a problem that comes back.
Hantavirus in California: where it is and how to clean up safely
California reported four hantavirus cases in 2025 in the CDC's provisional count, the most of any state, and the story behind each is usually the same: deer mouse droppings in a cabin, garage, or shed, disturbed in an enclosed space. Deer mice live in rural and foothill areas, not city centers, so the risk is concentrated outside Los Angeles and San Jose proper. The cleanup rule is the same everywhere. Open the doors and windows and leave for 30 minutes. Wearing gloves, wet the droppings with 1.5 cups of bleach in a gallon of water, wait five minutes, then wipe everything into a bag with paper towels. Never sweep or vacuum. For heavily contaminated outbuildings, hiring a provider with respirators and bagging is the safer choice. The CDC's long-run numbers, 890 cases since 1993 with 35 percent fatal, are the reason the rules are strict. They are not a reason to panic over a mouse in a Fresno kitchen, which is almost always a house mouse.
Preventing rodents in California stucco and tile-roof homes
Start with the roofline, because that is how roof rats get in. Close open tile ends at the eaves with bird stop or hardware cloth, and replace screen on attic vents with 1/4-inch hardware cloth. Then the garage. UC IPM says a rat fits under a 1/2-inch gap, so a worn bottom seal is an open door. Replace it and check the side seals. Pack steel wool around the air conditioning line set and any pipe or cable penetration through the stucco. Manage food and water. Pick up fallen citrus, avocados, and figs every few days, and keep pet food and chicken feed in metal bins. With only about 15 inches of rain a year, a dripping hose bib or pet bowl is the wettest spot on the block. In foothill homes, keep sheds free of stored food and bedding. Under California's bait rules, prevention is most of the plan.