A wet winter and a dry summer, and what each one does
Rodent pressure here follows the rain rather than the thermometer, which is different from most of the country and worth planning around. Through the dry half of the year, with highs near 93F and very little rainfall, water is the organizing resource. Animals arrange their nights around irrigation, hose bibs, condensate lines and anything else that stays wet, and buildings become attractive for shade and cooling rather than warmth. Chewed drip tubing is a common first sign in this stretch. When the rain arrives, the picture flips. Most of Sacramento's 20 inches falls in the cooler months, and on flat ground only 30 feet above sea level it soaks in rather than running off. That softens soil for Norway rat burrows against foundations and under decks, and the September to November window is when animals start working their way indoors. Winter itself is not a reset. A low averaging 39F is mild, so what got in stays in and keeps breeding, and what stayed out survives to try again. The scheduling conclusion is simple. Do the sealing in August and early September, when the ground is dry enough to work, the roof is safe to walk, and you are ahead of both the rain and the move indoors.
Overhead or at ground level
The single most useful thing to establish early is the height the animals are using, because a plan aimed at the wrong one leaves the real door open. Roof rats come in from above and travel a long way to do it, more than 300 feet between a nest and a food source by University of California's measure. Mature trees, vines, fences, cables and downspouts all serve as approaches, and at the top they need very little: a torn vent screen, a soffit gap, a junction between roof planes, a vent stack boot that has hardened and cracked. Norway rats stay low. They dig burrows two to three inches across in soil that the winter rain keeps workable, then enter at grade through a door with too much clearance, a broken foundation vent or a utility penetration filled with something soft. The evidence is different for each. Noise overhead after dark, droppings on attic insulation and hollowed fruit point up. Burrow openings, runways worn through ground cover and droppings along a wall base point down. A proposal that covers only one height is not wrong so much as incomplete, and incomplete is what produces a quiet fortnight followed by a return.
What to ask a provider now that bait is restricted
California's product rules changed what a rodent company can actually do, and the differences between proposals now sit mostly in labor and materials rather than in chemistry. Start with the trapping schedule. Because most anticoagulant uses are prohibited, snap trapping is doing the removal, and that only works if somebody returns to check and reset. Ask how many visits are included, on what dates, and what triggers an additional charge. Then ask what, if anything, is being applied. Bromethalin, cholecalciferol and zinc phosphide remain under limited conditions, and a provider should be able to say plainly what they intend to use, where it would be placed, and how pets and non-target animals are protected. Vagueness here is a signal. Third, ask about materials. Hardware cloth, sheet metal and mortar are what hold up. If the answer involves foam or caulk as the primary closure, the repair has a short life. Finally, ask what happens if activity resumes in six weeks. A confident answer involves returning to find the missed opening. A weaker one involves adding more traps in the same places, which treats the symptom you already knew about.
Renting, owning, and who fixes the building
The repairs that end a rodent problem are structural, which means in a rented home the person seeing the droppings is usually not the person who can authorize the fix. If you rent, the useful move is a record rather than an argument. Photograph droppings with a visible date, note the room and the hour you hear activity, and keep copies of what you reported and when. Then ask for something specific: sweeps fitted so door clearances are under half an inch, crawl space vents screened in metal, branches cut back from the roof. Naming the repair changes the conversation from whether traps were set to whether the building was closed. If you own rental property in Sacramento, the arithmetic favors sealing. Roof rats reach attics on climbing routes that grow back every year, and with bait options narrowed, a recurring service that leaves the structure untouched now delivers less than it used to for the same monthly cost. Trimming and metal work in late summer is the cheaper path across three seasons. Either way, the housekeeping half still helps: food in hard containers, trash out rather than stored indoors, and fruit picked rather than left to fall.
What a thorough first visit should produce
You can judge a rodent company by where it spends the first hour and what it hands you at the end. Expect the exterior circuit first: burrow openings in soft soil, runways through ground cover, the clearance under every door, the condition of crawl space and foundation vents, each point where a pipe or conduit passes through a wall, and every branch, vine or fence that touches the building. In a neighborhood with mature trees, the vegetation survey matters as much as the hole survey. Then the attic and the crawl space, because that is where the evidence lives. Droppings on insulation, rub marks along framing, daylight at a soffit and nesting material all tell you which route is in use and roughly for how long. What you should walk away with is written and checkable: openings found with locations, the material that closes each, which trees need cutting, where traps are going, the dates someone returns, and what is deliberately excluded from the price. A single figure with no punch list attached has told you what something costs without telling you what it is. Ask for the list before you decide, and compare lists rather than numbers.