Detecting bed bugs, especially at the beginning of the infestation can be difficult as there won’t be that many bugs or eggs to find. It doesn’t help that they are nocturnal insects, feeding mainly at night and staying hidden during the day. Because of this, the opportunity to detect the start of an infestation can be missed.

Bed bugs are now a serious problem and infestations have increased significantly over the years, but infestations are also often initially misidentified allowing the bed bugs more time spread.

So, looking for the early signs such as stains on the mattress and bedding, bites, live bugs, and eggs will give you a head start in detecting and eliminating these pests.

Several immature bed bugs on mattress seam.
cluster of bed bugs on mattress


Here are some of the first signs of bed bugs:

  • Rusty colored blood spots or stains on the bed sheets or mattress due to bed bugs being crushed when you roll on to them. Or the bite from the bed bug has bled for a while after it has finished feeding.
  • Itchy red welts may appear on exposed skin areas, such as the face, arms, shoulders, hands, back, or anywhere not covered when in bed.  You might not realize you have a bed bug problem until you or a member of your family is actually bitten and swelling on your skin appears.  However, not everyone develops itchy and inflamed skin though.[1]

    It isn’t uncommon when two people are sharing a bed and only one shows signs of bites. It isn’t possible to say for definite if the welt is caused by a bed bug as skin reactions vary from person to person and also because of their likeness to other insect bites.

    Some skin conditions and infections can also be mistaken for insect bites. Keep this in mind if you don’t find any other evidence of bed bugs as you might have a different pest problem.

  • Dark fecal stains or smears (which are dark brown or black) on mattresses, walls, furniture, carpet edges, etc.  Bed bug fecal matter is the size of a small dot and usually bleeds into the fabric and looks like smeared ink.  As horrible as it sounds, this is your blood the bed bug has taken up for its blood meal and has digested and pooped out!

    As bed bugs like to stay close to their food supply, always start by looking in the corners of the mattress and along the mattress piping for stains and bugs as these are prime areas to look for signs.

  • Eggshells and shed skins (exoskeleton) that nymphs leave behind when growing. The shells look like the bed bug except that they are translucent.

  • Offensive smell.  Bed bugs smell because the glands on the underside of their body produce an unpleasant, musty-sweet odor, and this odor is one of the characteristic signs of a bed bug infestation. The smell has been likened to a wet towel.

  • And of course, live bed bugs you see crawling around.  One of the questions I get asked a lot is whether bed bugs crawl on walls and ceilings.  The answer is yes they do! They like to harbor in and near to where you sleep and have many hiding places.
image of various bed bugs life stages on box spring instars to adults
various life stages bed bugs on box spring

It’s easier and far less expensive to treat an infestation in its early stages. So if you suspect you have bed bugs, it is best to try and detect and treat the infestation before it spreads and becomes established.