(NEXSTAR) – Are you living in a rat-infested nightmare-scape? If you live in a major city, the answer is likely yes. But there’s a good chance you’re not living in the country’s most rat-infested nightmare-scape — at least according to the findings from a national pest control company.

This week, Orkin released its 2021 list of the “rattiest cities” in the U.S., which ranks 50 of the nation’s busiest metro regions by “the number of new rodent treatments” performed in the last year. Specifically, Orkin studied new rodent treatments executed between Sept. 15, 2020, and Sept. 15, 2021, at both residential and commercial properties.

Taking the top spot in 2021 — and keeping its streak alive — is Chicago, a city deemed by Orkin to be the “rattiest” in the country for a seventh straight year.

Los Angeles, New York, Washington, D.C., and San Francisco rounded out a top five that remained unchanged since 2020’s list. Baltimore, meanwhile, climbed two spots to #6, knocking Detroit down to #8 and overtaking Philadelphia, whose ranking remained steady since 2020 at #7.

While the top “rattiest cities” of 2021 remained largely unchanged, many of the cities on the lower portion of the list had shifted or clawed atop each other, like so many rats in a nest. Most notably, Portland, Maine, climbed 26 spots to #38, marking its very first appearance in the top 50 since Orkin began its rankings.

Orkin says the rats themselves were also becoming more unpredictable in their behavior, partially as a result of COVID-prompted shutdowns.

“The pandemic-driven closure of restaurants forced rodents to find new food sources,” reads a press release issued by Orkin this week. “Without food waste to consume, these pests were seen scavenging new areas and exhibiting unusual or aggressive behavior.”

The company further urged homeowners or apartment dwellers to stay vigilant when it comes to rodent infestation.

“After a year of depleted resources, residential properties offer the ideal habitat for rodents, and once they’ve settled in, they’re capable of reproducing rapidly and in large quantities,” said Ben Hottel, an Orkin entomologist who was quoted in the press release.

A full list of Orkin’s “rattiest cities” can be found below, with plus(+) or minus(-) symbols indicating their change over last year’s list:

  1. Chicago
  2. Los Angeles
  3. New York
  4. Washington, D.C.
  5. San Francisco
  6. Baltimore (+2)
  7. Philadelphia
  8. Detroit (-2)
  9. Denver
  10. Cleveland (+1)
  11. Seattle (+1)
  12. Minneapolis (-2)
  13. Boston
  14. Indianapolis (+1)
  15. Atlanta (-1)
  16. Pittsburgh (+2)
  17. San Diego (+2)
  18. Houston (-1)
  19. Cincinnati (+3)
  20. Dallas (-4)
  21. Hartford, Connecticut. (+6)
  22. Milwaukee (+2)
  23. Miami (-3)
  24. Portland, Oregon (-1)
  25. Kansas City (+5)
  26. Columbus, Ohio. (+2)
  27. Norfolk, Virginia. (-2)
  28. Richmond, Virginia. (+5)
  29. Sacramento (+7)
  30. St. Louis (+7)
  31. Albany, New York (+7)
  32. Grand Rapids (-3)
  33. New Orleans (-12)
  34. Flint, Michigan. (+8)
  35. Raleigh, North Carolina (-9)
  36. Nashville (-2)
  37. Champaign, Illinois (+2)
  38. Portland, Maine (+26)
  39. Burlington, Virginia. (+8)
  40. Louisville, Kentucky. (+13)
  41. Buffalo, New York
  42. Charlotte (-11)
  43. Phoenix (-11)
  44. Greenville, South Carolina (-9)
  45. Green Bay
  46. Syracuse (-2)
  47. Charleston, West Virginia (+4)
  48. Dayton (+1)
  49. Albuquerque (-1)
  50. Tampa (-9)

More information on discouraging the presence of rodents can be found at the Centers for Disease Control and Prevention.