What Do Bed Bugs Look Like? Eggs, Nymphs and Adults


It can be hard to answer the question “What do bed bugs look like?” in part because, like all insects, they go through multiple stages of development and they look different at different stages.

Most of the time, if you look up information on bed bugs, these sources talk a lot about what adult bed bugs look like. Pieces on the topic often give short shrift to what the “babies” (nymphs) or bed bug eggs look like and the fact that adult males and adult females look a little different from each other.

That may seem weird, but humans don’t look the same at birth as they do as adults either. They are a very different size and have different proportions. We just are familiar with human babies, so it seems obvious to us that human babies are the same species as we are. But it’s really not so obvious.

In this post we are going to cover both: What adult bed bugs look like and also what their eggs and baby bed bugs look like.

Why Bed Bugs Are a Serious Problem

That brings us to the question of why people care so much about bed bugs. Bedbugs tend to live in colonies of anywhere from four to five hundred individuals and, like female mosquitoes, they need human blood. They feed, then molt repeatedly, getting bigger, and eventually lay eggs.

So, they bite people who are sleeping, leaving small bite marks. These bites are typically accompanied by a small round rash.

Picture of an adult bed bug – @ jareynolds / depositphoto

It may not be a big deal if you wake up with a few bites. But a large colony of bed bugs can leave you covered with dozens or hundreds of bites in a night. If the bites are not kept clean, they can become infected and lead to additional complications. Sometimes, people also react allergically. As with any allergic reaction, this can be a serious issue requiring medical attention.

Historically, bed bugs were not deemed to be a public-health threat because they were not known to transmit disease. However, that assessment changed not all that long ago when a study from Penn Medicine found that they are capable of being a vector for Trypanosoma cruzi, the parasite that causes Chagas Disease.

This is the feared disease that “kissing bugs” transmit. That’s not exactly shocking given that bed bugs and kissing bugs are actually distant cousins. If you aren’t familiar with it, Chagas Disease is a relative of African Sleeping Sickness and it can be deadly.

Description of What Bed Bugs Look Like

Getting back to what they look like, most pictures of bed bugs show adult bed bugs. They are quite small. The largest specimens only get to be one quarter of an inch in length.

They are roughly the size and shape of an apple seed, with a cluster of legs up near the head at the pointy end. They are generally reddish brown in color. Like an apple seed, they are flat if they haven’t fed.

If they have recently fed, they can be more reddish than brown and their body will elongate and be less flat. This is because they are filled with blood — probably your blood if it is your bed. When they are full of fresh blood, the body tends to look less broad as well. Again, this is because of being full.

Think how a Mylar balloon can be perfectly flat. When you add helium to it, it not only puffs up, it looks less broad than when it was flat and had nothing in it.

Cimex hemipterus (tropical bed bug) – Photo: @ smuayc / depositphoto

The body shape varies a bit for adult males and adult females. Unfed male bodies often appear to be slightly more oval or elongated. On the other hand, unfed female bodies often appear to be a bit rounder in their shape. After they have fed, the differences in their shape become less recognizable.

They both have a set of lines across the main body, making it look a little like a ladder effect. The main difference between both bed bug sexes is the following: Males have a pointy tip to their abdomen.

Also bed bug eggs, like bed bugs, are hard to find. A female bed bug lays up to 12 bedbug eggs in one day and up to 200 during her lifetime. These have an approximate size of 1mm, are slightly transparent and creamy white. Discovering the hiding places for bed bug eggs is very important if you want to get rid of bed bugs completely.

Newly hatched bed bugs are really tiny, like the head of a pencil. They are not much more than a dot. They are clear, unless they have recently fed. If they’ve recently fed, they are bright red.

Here is a quick run down of the traits of baby bed bugs:

What Do Baby Bed Bugs Look Like?

  • About the size of a dot.
  • Clear or red in color.
  • If they are red, they have recently fed on blood.
  • They don’t move all that fast.

What do Bed Bug Eggs look like?

  • Approximate size of 1mm.
  • Slightly transparent.
  • Creamy white.
What do bed bugs look like during different life stages – Photo: blueringmedia / Depositphotos

Here is a quick run down of the traits of adult bed bugs:

What Do Adult Bed Bugs Look Like?

  • Flat oval reddish-brown body.
  • The color turns more red than brown when they feed.
  • They look similar in size and shape to an apple seed, but with legs at the pointy end.
  • The body shape differs a bit, depending on gender.
  • Females are a bit rounder.
  • Males are a bit more oval / elongated.
  • They have lines across the main body, making it look a little ladder-like.
Adult bed bug – @ jareynolds / depositphotos

Where Are Bed Bugs Found?

Bed bugs are typically found in beds, such as between the mattress and box springs or in the bedding, and can sometimes be found in upholstered furniture. Like so many insects, the first sign of them that you notice may be poop marks. You might also notice bites before you notice the insects.

The bugs themselves often go unnoticed because they are both very tiny and very flat, which helps them hide in surprisingly small spaces.

When looking at pictures of bed bugs, remember that these are typically enlargements. The actual bugs are quite tiny in size. The babies are like little dots from a pencil and the adults don’t get bigger than one quarter inch. So close ups to delineate how they look are almost always larger than their actual real life size.

So, if someone asked you “What do bed bugs look like?” could you tell them now? Just remember the babies look like clear or read pencil dots that run around and the adults look like reddish-brown apple seeds with legs and antennae up front.

For Further Reading:

Penn Study Shows Bed Bugs Can Transmit Parasite that Causes Chagas Disease
Bed Bug FAQS from the CDC
How to Prevent Bed Bugs
How to Get Rid of Bed Bugs

Cover photo: @ jareynolds / depositphotos

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