Bed bugs can make a home inhospitable. They can be a huge cost to remove as well.

Orkin, a nationwide pest control services company, says its revenue from bed bugs treatments are up more than 10 percent over last year. The problem is growing.

“We have more people affected by bed bugs in the United States now than ever before,” says Ron Harrison, Orkin entomologist and director of technical services. “They were virtually unheard of in the U.S. 10 years ago.”

Bed bugs can travel from place to place relatively easily, attaching themselves to your luggage, purse, or other belongings and ultimately then settling into your home or apartment.

“Anyone can get bed bugs in their home. They are not a sign of uncleanliness,” Harrison says. “Bed bugs only need blood to survive. We have treated for bed bugs in everything from million-dollar homes to public housing.”

Bed bugs are small (about the size of an apple seed, fully grown), so they can be difficult to detect. Also, they can survive up to a year without feeding.

They often hide around seams of a mattress, behind headboards and in cracks and crevices, usually within a five-foot radius of the bed, Orkin notes. One of the first signs is spotting a bed bug or evidence of a small dark stain that they may have left behind.

“People may have bed bugs and not know it, because many people have no physical reaction to bed bug bites,” Harrison says. “That’s why it’s important for people everywhere to inspect for bed bugs regularly.”

Orkin recommends homeowners and travelers do the following to prevent bed bugs spreading at their home:

• Inspect your home regularly for any signs of bed bugs. Check locations where bed bugs hide during the day, including mattress seams and behind baseboards, headboards, electrical outlets, and picture frames.

• Inspect all secondhand furniture carefully before bringing it inside your home.

• Wash any potentially infested bed linens, curtains, and stuffed animals on the hottest temperature allowed for the fabric.

• Contact a pest management company if you spot any signs. Bed bugs can quickly elevate to a major problem if they spread from room to room and start to multiply.

States With the Most Bed Bug Cases

Orkin recently released its list of top bed bug cities. The list is based on treatment data from the metro areas where Orkin preforms the most bed bug treatments for residential and commercial buildings from December 2015 to Nov. 30, 2016. The cities that topped its list are:

1. Baltimore

1. Washington, D.C.

1. Chicago

1. New York

1. Columbus, Ohio

1. Los Angeles

1. Detroit

1. Cincinnati

1. Philadelphia

1. San Francisco-Oakland-San Jose, Calif.

1. Richmond-Petersburg, Va.

1. Raleigh-Durham, N.C.

1. Cleveland-Akron-Canton, Ohio

Source: Orkin