Is your city crawling with bed bugs?

Miniscule andblood-sucking, bed bugs are a growing public health problem in the United States.

And they are a big problem in New York City and Philadelphia. Both ranked among the worst cities in the nation for bed bugs, according to an annual list by pest control company Orkin that was released Tuesday.

Orkin ranked the top 50 bed bug cities, with New York City coming in at No. 4 and Philadelphia at No. 9.

Rank is determined by the number of treatments the company performed in a given city from Dec. 1, 2015, to Nov. 30, 2016.

Baltimore topped the list with the worst bed bug infestation, followed by Washington, D.C., and Chicago. New York and Columbus, Ohio, rounded out the top five.

“We have more people affected by bed bugs in the United States now than ever before,” Orkin entomologist Ron Harrison said in a statement.

“They were virtually unheard of in the U.S. 10 years ago,” he said.

Gotham’s position jumped from No. 18 in 2014 to No. 4 in 2015, and remained there last year. Meanwhile, Philadelphia slightly improved, going from No. 6 in 2015 to No. 9 last year.

Boston improved slightly, going from No. 25 to No. 28.

Bed bugs are seasoned travelers. They latch onto purses, luggage and other belongings, and tag along to homes, apartments, hotels and public places, according to Orkin.

“We have treated for bed bugs in everything from million-dollar homes to public housing,”Harrison said.

Aside from their spread, bed bugs are also dangerous. Bites can spur allergic reactions and skin infections, and infestations can spark anxiety and insomnia, among other reactions.

Despite the name, they’re not only found in beds. Smaller than an apple seed, bed bugs hide in cracks and crevices in headboards or bed frames. So even if your mattress is clean, your home might not be.

Orkin released a list of tips to keep your home free of the pests:
— Inspect your home regularly for signs of bed bugs, especially during the day when they’re hiding in such places as baseboards, headboards, electrical outlets, picture frames and mattress seams.
— Decrease clutter to make inspections and detection easier.
— Inspect all second-hand furniture before bringing it inside the home.
— If linens, curtains and stuffed animals are potentially infested, place them in the dryer on the hottest temperature allowed for the fabric.