PORTLAND, Ore. (KOIN) — Seen a rat in Portland recently? You’re not alone: one Portland-based pest management company estimates it has seen about a 400% increase in rat-related calls since 2020.

TJ Jackson, an operations manager at local pest control company Interstate Pest Management, said that the rat population had already been growing drastically pre-pandemic, about 10 to 20 years ago. “Portland’s not to [New York City’s] level, but it’s a growing city,” he said. “You can expect that infrastructure and stuff like that will have to be adjusted to basically address that issue.”

Last year, pest control company Orkin did a study on the ‘rattiest’ cities in America. The study was based on the number of new rodent treatments performed from Sep. 15, 2020 to Sep. 15, 2021. Out of the list of 50 cities, Portland was ranked at No. 24.

Jackson believes Portland’s growing rat population has more of a relationship with backyard gardening and chicken coops than it does with homelessness and COVID-19. “If you had a garden, well now you have healthy rats,” he said. 

According to Jackson, there are two species of rats that they typically deal with in the pest management industry and neither is native to North America. There is the black Rattus rattus, also known as the roof rat, and the brown Rattus norvegicus.  Because these rats have been imported from their natural habitat, they are fully dependent on their relationship with humans. 

“They have no native habitat here in Portland,” Jackson said. “All the habitat here is being created by us. Rats are just adapting and manipulating it.”

Jackson, who grows his own food at home, does not want to discourage anyone from doing so. But there are habitat adjustments that can be made such as elevating chicken feed or moving it at night so rats can’t access it.  

Furthermore, he said, “I don’t put rodenticides or traps in my garden. What’s it going to do? The rat knows where the tomatoes are. He’s going to the tomatoes. He’s not going to go into the rat trap.”

While many people use traps to get rid of rats, that alone is not solving the problem. Jackson suggests that people make adjustments based on what is drawing the rat in.

“Everything you do to control them is going to resemble a scene from Tom and Jerry where you’re just chasing rodents around your house,” he said. “That show was on for 50 years, he never catches him because he’s not manipulating the habitat in any meaningful way.”

Another factor contributing to Portland’s ever-growing rodent population is the aging buildings. “Many houses now are reaching 100 years old, and old construction offers lots of harborage opportunity,” The operations manager said. “Then you pair that with the new development taking place all over the city, and you kind of have this cycle of harboring rats and displacing rats at the same time.”

Calling a local exterminator is a great starting point for keeping rats away, but there are other ways people can combat the issue themselves. For example, keeping pets and pet bowls off of the porch is one way to eliminate a potential source of food for rodents. Jackson said there are also Youtube tutorials that show people how to keep rats and other animals off of their property.

In addition, Portlanders should be aware of any openings in their homes. “A rat needs half an inch to get into your house,” Jackson said. “A mouse needs a quarter inch to get into your house. I tell people if you can stick your pinky in it, a mouse will get in. If you can stick your thumb in it, a rat will get in.”

Multnomah County has other resources for pest prevention.