For minor and recently established infestations, it often takes even the pest professionals hours of searching to determine that you’ve got bed bugs. However, most cases proliferate from this stage, so it’s usually just a matter of looking around for a few common signs of bed bugs. Knowing what to look for can save you from an itchy bed bug rash or even a lawsuit by helping you avoid the tiny biting bugs in the first place.
1. Mattress Stains
Since bed bugs feed on blood, they leave a telltale rusty color behind when they’re squashed against the mattress or just void themselves so they can gorge on more fresh blood. This results in brownish red stains that may be tiny pinpoints or larger smears. You may find these stains on the top of the mattress, but the edges and sides of the mattress and box spring are a more common place to spot them. Lift the mattress up and look between it and the box spring. This commonly reveals either rusty smudges or entire colonies of bugs when there’s a heavy infestation.
2. Dark Spots
Bed bugs are happy to live up to 20 feet away from their usual feeding spot, like a bed, so you must expand your search beyond just the mattress. Look for dark spots about the size of a ballpoint pen’s tip along baseboards, around light switches and outlets, and other areas with fine cracks that the bugs can hide in. These marks are the fecal spots left behind by adults, and they’re not commonly caused by other types of home infesting insects. If the dark spots are on a soft material like fabric, you may notice a bleed of the color that spreads out from the spot. This is a concrete sign that you’re dealing with bed bug droppings.
3. Edge Colonies
While bed bugs can make a colony practically anywhere there is a crack big enough to pass a credit card, they do prefer to stay close to where humans and pets congregate for them to feed on. This is why one of the standard tests for bed bugs is to take the sheets off the bed and check around the rolled edge seam found on most mattresses. In most bed bug infestations, there will be at least one colony full of adult bed bugs, cream-colored larvae, and tiny white eggs. If not, you may at least find rusty spots and fecal stains to give you some advanced warning. Any edge or seam like this can hold colonies, so try checking between couch cushions, under labels and tags, and where the bed meets the headboard and frame.
4. Sweet Odors
Finally, heavy bed bug infestations create a distinctive sweet odor that can be detected by those familiar with the smell. This is hardly a diagnostic tool to base an entire pest control cleaning around, but it does help you determine if you see bed bug droppings or the remnants of other pests. Bed bug bites are not considered a good diagnostic tool since they can resemble bites from practically any other source, but they can be used as evidence in a court case.