Learning that a bed bug shed skin in or around your bed is one of the surest signs you have a big problem on your hands. This cast skin is actually the molted exoskeleton of the bug and indicates a bed bug infestation may be in full swing.

The molting process (called ecdysis) leaves this telltale bed bug evidence behind. Bed bugs go through five stages of maturing before becoming an adult. At each immature stage, the bug molts after a blood meal. Here’s what you need to know in order to spot discarded skins.


Shed bed bug skin looks almost identical to a live bed bug. The difference between a skin and an actual bug is that the exoskeleton will appear empty and translucent and obviously cannot move. Newer infestations have fewer shed skins because adults don’t molt. As the infestation wears on and mating continues, immature bed bugs begin to make up the majority of the population. At this point, each adult bed bug has already molted several times. Since shed skins do not decompose at the same rate, they start to build up over time.

This means you have a better chance at spotting the clear bed bug exoskeletons than actual bed bugs, especially since the skins will be found in large clusters along the mattress seams, box spring, headboard, baseboards and even stuck to your bedding and pajamas.

You will find various sizes of bed bug skins depending on the stage of life:

  • Bed bug egg – 1 mm.

  • First-stage instar nymph – 1.5 mm.

  • Second-stage instar nymph – 2 mm.

  • Third-stage instar nymph – 2.5 mm.

  • Fourth-stage instar nymph – 3 mm.

  • Fifth-stage instar nymph – 4.5 mm.


Bed bugs shed only after they complete a blood feeding at each of the first five stages of their lives. Depending on the availability of food (i.e., blood sources) and temperature, each stage lasts approximately one week under ideal conditions. If conditions are too cold or food is not readily available, each molt and subsequent shedding can take longer.


When you find bed bug skins, stop your search immediately. Continuing the search or cleaning up can disturb the living bugs, causing them to scatter and hide. This potentially spreads the infestation to other parts of your home. Instead, call Terminix® to get rid of bed bugs and their dirty skins.