No one likes rats in their basement. They bring disease and contaminate anything they get into. At the first sign of a rat in the basement, you need call for immediate pest control. Otherwise, that one rat will end up becoming dozens within a few weeks.
The first priority is to find out how they are getting inside the basement. You can get rid of the rats you already have, but if you don't stop how they are getting inside they will just come back. That's why rat exclusion is a priority over calling the exterminator.
There are two common rat species in the United States: the Norway Rat, which tends to like basements, and the Roof Rat, which likes higher places like the attic.
Finding the entry point means inspecting the entire house, from roof to foundation. Rats can come in anywhere. Once they get in, they can go down through the walls and into the basement, where they make their home.
Start at the basement level. Look for openings in ground-level vents or around the windows. Also, check anywhere a pipe leads into the house. Even a small gap is enough for a rat to get inside. If any part of your home has a crawl space, get under there and see if there are any holes that would allow access. For example, you might have electrical or communications cable going through the floor, leaving an opening.
Move up the side of your home, looking for places a rat can get in. Check your soffits and attic vents. Rats are exceptional climbers and can get in almost anywhere. If you have tree branches brushing the house, trim them back. Those may be the highways the rats are using to get to the basement.
Inspect your roof, especially around vents and chimneys. Any gap in the flashing can be an entry point to rodents.
When you find an entry point, plug it up. Rats leave pheromones as they move around the basement. These pheromones attract other rats, quickly enlarging the rodent population in your basement. Even a dead rat can bring other rats into the basement. Rat exclusion eliminates the paths the new rats can take.
You can nail boards across some openings. Stuffing insulation around pipe openings is another option. Spray foam can get into the smallest crevices. All of these are effective options for rat exclusion.
Rats live close to human populations because they have easy access to food and shelter. If you see one in your basement, there are plenty hiding close by. That's why you need to take immediate action on exclusion and trapping. Otherwise, you are going to have more rats than you can count.
Once you get the entry points closed up, the next step is to work on pest control inside the basement.
The most effective option for rat trapping is bringing in professional pest control. Trapping and baiting rats in your basement on your own is very messy and often ineffective. A professional exterminator has the traps and bait to capture and eradicate the rats throughout your home, including the basement. The exterminator will handle the trapping and mess for you.
The exterminator has special training on rat behavior that allows him to find where they are hiding and feeding. By concentrating rat exclusion efforts in those locations, the pest control expert can eliminate the population quickly.
If you have a rat problem in your basement, call for professional pest control right away. Let the exterminator handle the situation for you. They use effective trapping and bait to eliminate the problem.