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Pictures and Diagrams of Bed Bugs

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Bed bugs have three life stages and vary in appearance depending on the stage. They start in an egg that is 1mm in length and then are born into 5 baby (also called juvenile or nymph) stages (1.5mm to 4.5mm in length). This is followed by adulthood where the insect grows to approximately 3/8" (5.5mm long).

Bed Bug Actual Size Chart

chart depicting bed bug actual size at each life stageBed Bug Actual Size at Each Life Stage

A picture of bed bug at each stage of development is depicted below. Pictures are provided to make it easier when asking "how to identify bed bugs."

Pictures are also provided to help distinguish bedbugs from other insects which are similar in appearance.

Bed Bug Pictures

Picture of Bed Bug Nymph Feeding (left) and Adult (right)

What Does a Bed Bug Look Like?

Bed bugs move through 5 instars or stages on their way to adulthood.  After hatching they are about the size of a poppy seed. To pass from stage to stage, the need to take in a blood meal.  Bed bugs have a stylet on their head which is used to puncture the skin of their human host.  Photos and descriptions of each instar can be found below.

In favorable conditions it takes between 4 weeks  to 5 weeks to go from a hatched nymph to adult (at 83 to 90 degrees F).  A nymph or baby bed bugs can live for 3 to 4 months without a blood meal, adults can live just over a year.

confirming that you have bed bugs

The first signs of an infestation are usually bites on the legs, torso, neck or arms. Since the bites look like the bites of other insects such as mosquitoes, it is important to confirm the presence of the insects in other ways. This includes capturing an identifying an actual insect or the presence of fecal (black or brown marks) on a mattress.

To be sure, the easiest way to confirm that you have an infestation is to have a bed bug expert check a sample bedbug or have them come to your home.  Check our list of local bed bug experts here.

Diagram and Anatomy

Diagram of Bedbug

pictures of bed bug eggs

Bedbug eggs are the size of a sesame seed (about 1 mm).  They are white and oval shaped. On average, a 3 eggs a day are laid by females (for a total of 200 to 500 per female), which appear glued to the surface.  This is why vacuuming is not an effective way to pick up the eggs.

Eggs are killed with sprays that are specifically labeled as being able to penetrate the egg.  Steam via a hand steamer is also used to kill eggs as bed bugs and bed bug eggs are killed at 114F.

Bed Bug Egg on Surface

baby bed bugs

Nymphs are lite brown and are approximately 5/100 of an inch in length.  These baby bed bugs will change in appearance before and after feeding.  They need to feed in order to move from instar to instar.

Bed Bug Before Feeding on Host

Bed Bug Adults

Bed Bug Size Change After Feeding

Bed Bugs Change Color & Shape While Feeding on Host - Picture from Whitney Cranshaw, Colorado State U.

Adult bed bugs are approximately 3/16 of an inch long.  When you identify bed bugs, check the color which is   red/brown in color and look for a 3 segment beak and 4 segment antennae.  They have wings, which are referred to as being vestigial, meaning that they aren't used.  The bugs are covered by fine gold colored hair.

Dorsal (Head) View of Bed Bug

Picture of Bed Bug - Dorsal View

The bed bugs give off an odor that can be detected by dogs, which is why many bed bug pest control companies use dogs to identify places where bed bugs are hiding.

From a side view bedbugs are flat.

Bed Bug - Side View

A bed bug changes in appearance and size before and after feeding as shown below:  A bed bug feeds every few days, with feeding itself taking about 10 minutes.

Insects That Look Like Bedbugs

There are several insects that look like bed bugs.  If you aren't sure, send a picture or insect to the Cornell Diagnostic Laboratory for review ($25 charge).

Another approach is to ask a local pest control professional.  Check our list of local bed bug experts here or call Home Advisor at 1-877-233-1145.

Insects similar in appearance to bed bugs are shown below:

Bed Bug Compared to a Bat Bug

Side-by-side bed bug and bat bugBed Bugs are Similar in Appearance to Bat Bugs

German Cockroaches

Look for Young Roaches that look like bed bugs. They lay rectangular egg cases and fecal pellets. The color is more
brown than red.

Carpet Beetle and Warehouse Beetle

Carpet and Warehouse beetles may appear in beds feeding
on hair and feathers. Larvae may shed tiny hairs that cause skin itch. These insects do not bite people.

Shiny Spider Beetles

Shiny spider beetles are often confused with bed bugs and ticks. They feed on dried plant material, seeds, or dried meat and do not bite humans.

insects that bite


Each of these free brochures provides additional information on insects that bite.

Diagram of bed bug anatomy.
Available in a free Ebook

Overview of bed bug lifecycle and behavior. Bed Bug Pictures and lifecycle diagram.
Available in a free Ebook

Questions and answers

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University of Nebraska Department of Entomology

Harold J. Harlan, Board Certified Entomologist (B.C.E.)

Texas A&M

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