How an inspection maps entry points
a rodent inspection starts outside, because that is where the animals come from. The technician walks the foundation slowly, looking at every place the house changes material or plane: where siding meets slab, where the garage door track ends, where gas, water, cable and air-conditioning lines pass through the wall. Mice can enter through a gap of about a quarter inch, roughly the diameter of a pencil, and young rats through half an inch. Rub marks, the greasy smudges left by fur repeatedly brushing a surface, confirm which openings are active. The roofline gets equal attention on roof rat jobs. Attic vents with torn screens, gaps where fascia boards meet at corners, open soffit returns and the junction where a roof plane meets a wall are common entries. Any branch, vine, fence or utility line touching the house is noted as a bridge. Norway rat inspections focus lower, on burrows with fresh soil at the entrance, gaps under stoops and decks, and the crawlspace access door. Inside, the technician checks under sinks, behind the stove and refrigerator, the water heater closet, the attic hatch and the crawlspace. Droppings are judged for freshness: dark and soft means recent, gray and crumbly means old. Nesting material, chewed wiring and grease trails along joists are photographed. The result should be a list you can read yourself: each opening, its location, its size and the material proposed to close it. That list is the real product of the inspection and the basis for a fair exclusion quote.
Running a trapping program that actually finishes
Most failed trapping efforts fail on quantity and placement, not on bait. rodents travel along edges, so a trap in the middle of a floor is nearly useless. Snap traps go flat against the wall with the trigger end facing the wall, so the animal runs across the trigger from either direction. For mice, technicians set traps every six to ten feet along active walls and in pairs behind appliances, often a dozen or more in a single kitchen and garage. A small smear of peanut butter or a tuft of cotton for nesting is enough; a lump of bait lets the animal feed without tripping the trap. Rats need a different rhythm. Norway and roof rats are neophobic, meaning they avoid unfamiliar objects for several days. An experienced technician often places baited but unset traps on the first visit, then arms them once the rats have grown used to them. Rat traps go along the runways found during inspection: on top of attic joists, along the sill plate in a crawlspace, beside burrow entrances outside. Multi-catch and electronic traps have their place, but a well-placed snap trap remains the standard. Follow-up visits every two to four days keep catches from rotting, show which traps are producing, and let the technician move traps toward fresh sign. The program ends when several consecutive visits produce no catches and no new droppings, not when a certain number of animals has been caught. Trapping and exclusion should overlap, because sealing the house while rodents are still inside makes them more determined to chew a way out.
Exclusion materials and why foam fails
Exclusion is the part of rodent control that turns a temporary win into a permanent one, and material choice is where most of the difference lies. Rodent incisors grow continuously and are hard enough to gnaw through wood, plastic, aluminum screen, vinyl, drywall and cured spray foam. Foam looks appealing because it fills an irregular void quickly, but a rat can chew a fresh hole through it in a night, and it degrades in sunlight and shrinks in cold. Used alone, foam is a delay, not a barrier. What holds is metal or masonry. Quarter-inch galvanized hardware cloth, cut oversize and screwed over vents and larger openings, is the workhorse. Sheet metal flashing bent to fit goes at garage door corners, fascia gaps and the bottom edges of siding. Copper or stainless mesh, packed tightly into pipe penetrations and weep holes, resists gnawing and does not rust-stain like steel wool. Mortar or hydraulic cement closes gaps in block and brick. Doors get commercial-grade sweeps and, where rats have chewed a corner, a metal kick plate. Foam and caulk still serve as a backer behind mesh or a sealant over a metal patch to keep out insects and air. Good exclusion is mechanical: fastened with screws, not just adhesive, and overlapping the opening by an inch or more on every side. Ask what material goes at each opening and expect the quote to list them. A one-way door at the primary entry lets animals still inside leave without returning while other openings are sealed. A written re-entry warranty, commonly one to several years, signals that the provider expects the work to hold.
Cleanup, sanitation and monitoring after the rodents are gone
Once trapping has ended and the house is sealed, the remaining work is dealing with what the rodents left behind. Attics and crawlspaces with heavy activity hold droppings, urine-soaked insulation, nesting material and sometimes carcasses. Contaminated insulation loses its loft and keeps broadcasting scent that draws new rodents to the same spot. Cleanup crews remove it with HEPA-filtered vacuum equipment, disinfect exposed framing, treat for the mites and fleas that leave a dead host, and blow in new insulation. For light contamination, a homeowner can do the wet-wipe cleanup described in the hantavirus answer on this page. Hantavirus deserves specific mention because the standard cleanup instinct, sweeping, is the wrong one. The virus is carried mainly by deer mice and spread through dried urine, droppings and saliva that become airborne when disturbed. Infections are rare but serious. CDC guidance is to ventilate for at least 30 minutes, wear gloves and a well-fitted respirator, wet all material with disinfectant before touching it, avoid dry sweeping and vacuuming, and double-bag waste. Sheds, cabins and vehicles that have sat closed for months are the classic high-risk settings. Sanitation keeps pressure down afterward. Bulk food, birdseed and pet food go into sealed containers; grease behind the stove and open trash get cleaned up; woodpiles come off the ground and ivy comes off the wall. Monitoring closes the loop: a few unset snap traps or non-toxic monitoring blocks left in the attic and garage, checked monthly, will show fresh gnawing long before you hear scratching again. Providers with an ongoing plan typically include bait-station checks and a walk of the foundation on each visit, which is where new openings are caught early.
What the data says before you hire rodent control
The statements below are tied to named surveys, studies and published cost guides, and each one says what it does and does not prove. They describe patterns across many households, which is useful context, not a diagnosis of any one property. Garages and sheds are worth a look before winter: 32% of U.S. homeowners who had encountered rodents named them in the 2022 NPMA/Harris Poll, a multi-select answer from a lifetime survey, not a measure of how many garages are infested. The U.S. Census Bureau's 2019 American Housing Survey (AHS), reporting on selected large metros, found only 3.1% of occupied homes in Arizona's largest metro area had seen rodents or evidence of them in the preceding year, a sightings figure rather than a verified infestation rate. The U.S. Census Bureau's 2019 American Housing Survey (AHS) counted 2.9 million occupied homes that had seen both rodents and cockroaches in the preceding year, based on what residents reported noticing, not on verified infestations. Five point six times the likelihood of reporting rodent sightings was found for occupied U.S. homes with sloping, leaning or buckling outside walls in the U.S. Census Bureau's 2019 American Housing Survey (AHS); the association describes reports, not confirmed infestations, and does not prove cause. For most homeowners, pests are a when-not-if problem: 76% of respondents to HomeTeam Pest Defense's 2022 online survey of U.S. homeowners said they had faced one in the past year, though the figure is self-reported and the survey was sponsored by a pest-control company. Because every figure above has a stated population and date, you can cite it when comparing providers. What none of them can tell you is what your specific property needs; that still takes an on-site inspection.