More than half of travelers would steer clear of a hotel if even just one online review mentioned a bed bug sighting there, according to a new study of 2,088 people published in the journal American Entomologist. But less than a third of the study’s respondents would actually recognize a bed bug if they saw one in their hotel room.

Hotels tend to be perfect breeding grounds for bed bugs, says Michael Hansen, Ph.D., a senior scientist at Consumer Reports, because so many travelers pass through a single hotel room, and bed bugs—once they check in, often via a guest’s luggage—can be difficult to dislodge.

What’s more, says study author Michael Potter, Ph.D., a professor of entomology at the University of Kentucky, “more often than not, hotel rooms are not being preventatively inspected.” That’s why “travelers should be vigilant themselves.”

But to protect yourself against bed bugs when you travel, it’s important to know where to look for bed bugs and how to recognize them when you see them.  

Spotting Bed Bugs 101

1. Secure your belongings. Before you look for bed bugs in a new hotel room, store your zipped luggage away from the walls and off the floor and bed. That way if you find any signs of an infestation, you don’t risk taking it with you.

2. Probe their hiding spots. Remove all of the sheets and coverings from the mattress, and check closely along all the seams and on the headboard, especially near the head of the bed, Potter says. You’ll usually find bed bugs closer to the pillows because the heat and carbon dioxide produced by human breath draw them out of hiding.

3. Know what you’re seeking. Look for peppercorn-sized black spots—digested blood secreted by the bugs. This is the easiest way to detect their presence during the day, Hansen says. A variety of indoor bugs—baby cockroaches, for example—are sometimes confused with bed bugs, says Ameya Gondhalekar, Ph.D., a professor of entomology at Purdue University, but adult bed bugs have a distinct look: They are disk-shaped, flat, and reddish-brown. Adolescents are white, almost clear, and red when their abdomen is full of blood. Their eggs, small and white, are almost undetectable to the human eye.

More on Bed Bugs: At Home and on the Road

4. If you find some. Ask to change rooms immediately—and get as far away from your original room as you can. “Bed bugs tend to travel, and there is a higher probability there will be bugs in the adjacent unit,” Potter says.

5. When you get home. “Bed bugs are good hitchhikers,” Gondhalekar says. To help ensure that none take up residence in your home upon your return, take your clothes straight from your suitcase and throw them in the dryer, Potter says. Thirty minutes on high will kill the pests, according to the Environmental Protection Agency. Treating a suitcase is trickier: Ninety minutes at 120º F or higher should kill both bed bugs and their eggs, says the EPA, which recommends leaving luggage outside in a black plastic bag on a hot summer day.