How Do Exterminators Get Rid of Rats? 5 Steps

A professional rat job has five parts: an inspection to find which rat you have and how it's getting in, trapping, careful use of bait stations, sealing the entry points, and follow-up visits until the activity stops. None of it is magic. What a good exterminator brings is experience with rat behavior, access to products and equipment homeowners can't buy, and the time to keep at it. This guide walks through what they actually do, what's different from doing it yourself, whether fumigation kills rats, how long it takes, and when hiring someone is worth it.

Step 1: Inspection

Everything else depends on this. A technician looks for:

• Which rat it is. Norway rats burrow and stay low: crawl spaces, basements, garages, burrows along the foundation. Roof rats climb and stay high: attics, wall voids, along utility lines and fences. In North Carolina and Virginia, Norway rats are far more common; North Carolina's state mammal survey describes roof rats as rare and local, mostly around coastal port cities. In coastal South Carolina, both occur. See roof rats vs. Norway rats.
• Activity: droppings, gnaw marks, greasy rub marks along walls and beams, burrows, runways through plants, and noises at night. See signs you have rats in your walls.
• Entry points: gaps of 1/2 inch or more around the foundation, roofline, vents, utility lines and doors.
• What's attracting them: pet food, bird seed, fallen fruit, garbage, woodpiles, dense shrubs, and branches touching the roof.

Step 2: Trapping

The University of California's rat guidance calls snap traps "the safest, most effective, and most economical way to trap rats." The skill is in how they're used:

• Pre-baiting. Rats "quickly detect and tend to avoid new objects and new foods," UC says, and may avoid traps for the first several days, or even weeks. Roof rats are warier than Norway rats. So a common professional approach is to leave traps baited but unset until the rats have taken the bait a few times, then set them.
• Enough traps. UC's rule: if the bait is taken from every trap, double the number of traps, and keep doing so until some bait is left untouched. Too few traps is a common DIY mistake.
• Placement by species. For Norway rats: along walls, behind objects, in dark corners and where you find droppings. For roof rats: up high, on ledges, shelves, pipes, beams, fences and branches.
• Small bait. A pea-sized amount, so the rat has to work at the trigger.

Rats learn. On YouTube, under a video on rat traps, one commenter said glue boards don't work on rats because "they'll test it with their toes and then avoid it." Another, under a different rat-control video, said that once they caught one rat in a trap, "no other rat will go near the same trap." That's why technicians move traps and change baits. UC doesn't recommend live trapping for homeowners: the rats have to be humanely killed or released right where they were caught, and they're not native wildlife.

Step 3: Bait Stations

Most professional rat programs include locked bait stations, usually outside along the foundation and fence lines. This is where professionals and homeowners differ most:

• Stronger products. EPA restricted the most potent rat poisons (second-generation anticoagulants such as brodifacoum and bromadiolone) to professional and agricultural use. Store-bought rat poison now comes only as ready-to-use bait stations with block or paste bait, and loose pellets are no longer allowed in consumer products.
• Locked stations. UC says tamper-resistant stations must be used wherever children, pets or other animals could reach the bait, and every product's label rules have to be followed.
• The risks. UC warns that "exposure to even a single dead rodent might be enough to poison a pet," and that some baits can poison animals that eat the dead rodents. A highly liked comment under a YouTube trap video put the other downside plainly: poisoned rats often don't die right away, and may die "in your wall, under the house, or in the attic." That's one reason many professionals keep poison outside and trap inside. If it happens, see how to get rid of dead rodent smell.

Not used near homes: UC says smoke and gas cartridges aren't recommended for rats around houses, because Norway rat burrows can run under the home and the gas can get inside, and there's a fire risk. Carbon monoxide burrow devices can't be used within 65 feet of a building for Norway rats.

Step 4: Sealing Entry Points

Trapping and baiting remove the rats you have. Sealing is what stops new ones. That means closing gaps of 1/2 inch or more with materials rats can't chew, such as hardware cloth, sheet metal, and copper mesh or steel wool with caulk over it, not expanding foam alone. It also means fitting door sweeps and vent covers, and trimming branches back from the roof. For the full how-to, materials and cost factors, see rodent proofing your home.

Step 5: Cleanup and Follow-Up

A good rat job doesn't end on the first visit. The technician comes back to check and reset traps, refill bait stations, remove dead rats and look for new activity or new gaps. Droppings and nesting material should be cleaned up carefully. The CDC advises spraying droppings with disinfectant or a bleach solution and wiping them up rather than sweeping or vacuuming, which can stir up dust. Heavily soiled attic insulation sometimes has to be replaced, which is a separate and larger job.

Sealing and Trapping vs. Outdoor Bait Boxes

Ask around and you'll hear two philosophies. In one r/pestcontrol thread about rats in an attic (via Google search excerpts), the top answer was: "First close off every possible entry point! Then set snap traps to catch those still inside now unable to escape. It shouldn't take four trips." In another, a commenter said the traps inside are "peace of mind" while "the exterior rodent bait box does 90% of the work."

Both have a place. Outdoor bait stations reduce the number of rats around the house and show whether they're active, which helps where rats are living in the neighborhood and keep arriving. But bait alone doesn't stop rats getting inside, and bait inside a home risks rats dying in the walls. If rats are already in the attic or walls, sealing the entry points and trapping inside is usually what ends it. Ask any company you're considering which approach it uses and why.

Does Fumigation Kill Rats?

Yes. The gas used to tent and fumigate houses, sulfuryl fluoride, is registered as both an insecticide and a rodenticide, and the National Pesticide Information Center lists rats and mice among the pests it controls. The gas spreads into cracks and wall voids, so rats inside the house when it's fumigated will die.

But fumigation isn't a normal rat treatment. It's a whole-house treatment, usually done for drywood termites or bed bugs, and it's restricted to licensed applicators. It leaves nothing behind to keep new rats from moving in, and any rats that die inside the walls stay there. If your house is being tented for termites, it will kill the rats inside at the time, but you'll still need to seal the entry points.

How Long Does It Take, and Do You Have to Leave?

Most homes take a few weeks of visits, depending on how many rats there are, which kind, and how many ways in. Rats' wariness of new traps adds days at the start. On Reddit (via Google search excerpts), a commenter in r/pestcontrol warned that "the population is probably bigger than you think so it will take a few weeks." Another noted that rats that eat bait usually take 3 to 5 days to die. You don't normally need to move out for trapping, bait stations or sealing. Fumigation is the exception: everyone, including pets and fish, has to leave until the house has been cleared.

DIY or Hire a Professional?

DIY can work when it's one or two rats, you can find and seal the entry point yourself, and you're willing to use enough traps and stick with it. The tools are available to homeowners: snap traps, consumer bait stations and sealing materials.

A professional is usually worth it when:

• Rats are in the attic, walls or crawl space, or you hear them most nights.
• You can't find how they're getting in, or they keep coming back after you've sealed.
• The entry points are on the roof or hard to reach.
• You have children or pets and don't want to handle rodenticides.
• You've been trapping for weeks without it stopping.

The work is also unpleasant. One commenter on a YouTube attic video summed it up: people "CAN do each of these steps on their own, but most won't because it's a dirty, ugly task." For mice specifically, the same steps apply: the gaps they use are smaller (1/4 inch), so sealing takes more work. See how mice get into your house.

What It Costs

Rat control pricing depends on how many visits are needed, whether exclusion (sealing) is included, how much of the house is involved, and whether attic cleanup is needed. Exclusion and attic work are usually the biggest parts of the bill. For the factors that drive the price, see the cost section of rodent proofing your home, and see how much a mouse exterminator costs. Our rodent control service covers South Carolina, North Carolina and Virginia, including inspection, trapping and exclusion by licensed technicians.

If rats come back after treatment, it's almost always because an entry point was missed or a new one opened. See do rats come back after extermination.

Sources: University of California Statewide IPM Program, "Pest Notes: Rats" (74106); U.S. EPA, "Restrictions on Rodenticide Products"; National Pesticide Information Center, "Sulfuryl Fluoride General Fact Sheet" and technical fact sheet; CDC, rodent cleanup guidance; NC Parks, Mammals of North Carolina (roof rat); M. Eckerlin et al., "The Roof Rat, Rattus rattus, in Virginia," Northeastern Naturalist 29(2) (2022); Internet Center for Wildlife Damage Management, Norway rat and roof rat accounts; Reddit r/pestcontrol (via Google search excerpts); YouTube comments under rat control videos from The Pest Dude, Arrow Pest Service and Atticare.

Photo credits: Zeynel Cebeci, CC BY-SA 4.0; BrokenSphere, CC BY-SA 3.0 (cropped); via Wikimedia Commons.