(WHTM) — Orkin, a pest control company, has released its annual list of the top 50 rattiest cities and two Pennsylvania cities scurried their way near the top.

The company ranked metro regions by the number of new rodent treatments that were performed between Sept.1, 2022, to Aug. 31, 2023. The rankings include both residential and commercial treatments.

Philadelphia was ranked sixth on the list.

The nation’s rattiest city was Chicago, followed by Los Angeles, New York, Washington D.C., and San Francisco. Baltimore was listed as the seventh rattiest city.

Pittsburgh was the other Pennsylvania city to make the list. Ranked sixteenth, Pittsburgh was listed just after Indianapolis and just before Hartford.

According to Orkin, mice and other rodents enter about 21 million homes in the U.S. every fall. The company says it is common for them to come in between October and February to avoid the cold and search for food.

This poses health risks and property damage risks for home and business owners.

To help spot rodent infestation, Orkin recommends looking for certain warning signs such as droppings, gnaw marks, nests, rub marks, and strange noises.

Orkin also has some tips to prevent infestation. These include keeping food stored away, decluttering, maintaining landscaping, inspecting both the inside and outside of your home, and looking for possible entry points.

Sealing holes or cracks around your home and installing weather strips at entryways and under doors can help keep unwelcome rodents from getting in.