Bed bugs go to great lengths to stay out of sight, something they excel at thanks to their tiny size and flat shape. When they’re not sucking your blood—usually at night, but they can adjust to daytime sleepers—they prefer to hide in dark spaces where they can digest their meal, mate, and lay eggs. Even though you might not see the creatures, you can see evidence of them: These are the bed bug signs entomologists use.
Watch for bed bugs
If you’re sharp-eyed, you might spot the insect itself: They’re about the size of an apple seed. That’s why they creep up on you while you’re sleeping because they don’t want to be disturbed while feeding or when they are digesting their blood meal, mating or laying eggs in their harborage, hidden out of sight. They’re also quick and will scatter when you enter the room. Here’s where you can get a better sense of what bed bugs look like.
Watch for bed bug bites
A clear bed bug sign is a bite—which you’ll wake up with when they’ve been feeding on you at night. If you wake up feeling itchy and have red welts or bumps in a line or in several zig-zag clusters, that’s a good indication you’re dealing with bed bugs. The bugs have a numbing agent in their saliva so you don’t feel the bite, says Brittany Campbell, PhD, an entomologist with the National Pest Management Association (NPMA). The itching that most people feel stems from a mild allergic reaction to the numbing agent. The good news, she says, is that bed bugs are unlikely to spread disease, unlike other biting insects like mosquitoes.
Watch for bed bug poop
“Regardless of the blood source or host,” says Campbell, “once bed bugs digest their blood meal and excrete it, it appears as dark brown or black spots on a surface—very similar to what you would expect an ink stain to look-like if your pen leaked onto your clothing,” says Campbell. You might notice the spots on your sheets, mattress, box springs, or in the cracks and crevices of your headboard, nightstand, or other bedroom furniture. Other “droppings” are tiny blood spots. Sometimes bed bugs “overeat” and they excrete a few drops of blood that will appear as tiny red dots if the fabric or upholstery is a light fabric.
Watch for bed bug shells and eggs
Other bed bug signs include molted shed skins and eggs, says Campbell. “The molted skins are very thin and lighter in color but will be in the same shape as a bed bug since they are essentially the left-over skin of the bug.” You might be able to see eggs, though they are tiny—about the size of a pinhead—and whitish or translucent. Still, these are bed bug signs to look for when you check into a hotel room.
Watch for bed bug signs in other rooms
Bed bugs won’t stay in your bedroom—if you fall asleep in front of the TV on the couch or in a recliner, say, they’ll set up camp in the furniture nearby. “Bed bugs commonly infest sofas and chairs and can even hide unseen in chair legs, if the legs are hollow. The bugs will reside in any hidden crack or crevice of the sofa, including deep into the couch under the cushions, inside of the wooden structure of chairs and sofas or metal, as well as inside of screw holes and screw heads,” says Campbell. Just don’t look for the bugs in your hair—and don’t fall for these other myths about bed bugs.
Where else can I see bed bug signs?
You can find bed bug signs in curtains, walls, behind baseboards, wallpaper, picture frames, books, electrical switch plates, electronics—really, just about anywhere inside your home. They can also hitch rides: “Beg bugs are also known to survive in temporary or alternative habitats, such as in backpacks and under the seats in cars, buses, and trains,” says Campbell.
