What Do Bed Bugs Look Like? Pictures, Size and Color

Quick answer: Adult bed bugs are flat, oval, wingless insects about the size of an apple seed (5 to 7 mm, or 3/16 to 1/4 inch). They're reddish-brown when unfed and swell, get longer and turn redder after feeding. Young bed bugs are smaller and nearly clear or pale yellow, and eggs are pearly white specks about 1 mm long.^1,2,3

Found a small brown bug in your bed and need to know if it's a bed bug? Start with the quick checklist below, then use the photos and size chart to compare. This guide also covers how their color changes after they feed, how to tell them from look-alikes, and exactly what to do with a bug you've caught.

Is It a Bed Bug? A 30-Second Checklist

A bug is likely a bed bug if most of these are true:^1,3,7,5

• It's flat and oval, not long and narrow or round like a beetle.
• It's about the size of an apple seed or smaller, and reddish-brown (or bright red if it just fed).
• It has six legs and no wings you can see, and it crawls rather than flies or jumps.
• You found it on or near a bed, couch or other place where people sleep or sit for long periods.

If it matches, save the bug and get it identified, then check your bed for other signs. If it doesn't, compare it with the common look-alikes.

What Do Adult Bed Bugs Look Like?

Adult bed bugs (Cimex lectularius) are flat, oval and wingless, roughly the size, shape and color of an apple seed.^1,2,6 Up close, look for these features:^1,8,9

• Body: broad, flat and oval when unfed, thin enough to slip into a crack the width of a credit card.^1,10,11
• Color: reddish-brown or mahogany.^3,7,2
• Legs and antennae: six thin legs and two antennae with four segments.^1,6
• Mouthparts: a beak with three segments, folded under the head when the bug isn't feeding.^1,12
• Hairs: short, golden hairs over the body.^1,9
• Wings: only small pads, not real wings. Bed bugs can't fly, and they don't jump like fleas.^8,9,3

Although they can't fly, bed bugs crawl quickly across floors, walls and ceilings.³ A University of Tennessee timing clocked one bed bug covering about 6 inches in just over 4 seconds.¹³ They also have scent glands that can give a heavy infestation a sweet, musty odor, though the smell is rarely noticeable otherwise.^1,3

How Big Are Bed Bugs?

Bed bugs are small but visible. Here is how big each stage gets, using sizes from the U.S. Environmental Protection Agency:¹

The Centers for Disease Control and Prevention (CDC) puts it another way: bed bugs range from 1 mm to 7 mm, "roughly the size of Lincoln's head on a penny."⁵

Bed Bug Color: Brown, Red or Black?

A bed bug's color depends on its age and how recently it ate:

• Brown or reddish-brown: unfed adults.^1,3,7
• Bright red: adults and nymphs that have just fed. They also swell and stretch out, so a fed adult looks longer and rounder, almost like a tiny football.^1,2,10
• Dark or nearly black: bugs that are digesting a meal. Over a couple of days the blood darkens, and the belly can look blackish or show a black spot.^2,12,10
• Clear, white or pale yellow: young nymphs that haven't fed yet.^1,2,13

Are there black bed bugs? Not as a separate kind of bed bug. A "black bed bug" is usually a regular bed bug partway through digesting its meal. If the small black bugs you're finding are round and shiny, or gather at windowsills, they're more likely carpet beetles.^2,10,14,15

What Do Baby Bed Bugs and Eggs Look Like?

Young bed bugs, called nymphs, look like smaller, paler adults. They molt five times before becoming adults and need a blood meal before each molt.^13,8 Unfed nymphs are clear to whitish-yellow and can be nearly invisible. After feeding, they turn bright red and look like a plump raspberry seed.^1,2,16

Bed bug eggs are about 1 mm long, pearly white and shaped like a tiny bean or grain of rice.^1,10 Eggs more than five days old show a red eye spot through the shell.^1,2,17 Learn more in our guide to bed bug eggs.

Can You See Bed Bugs With the Naked Eye?

Yes. Adults, nymphs and eggs can all be seen without a microscope.⁴ Adults are the easiest. The hardest to see are eggs and newly hatched nymphs that haven't fed, which are pale and about the size of a pinhead.^1,3,2 A flashlight and a magnifying glass make checking much easier.³

You'll often spot the signs they leave before you see a bug: tiny dark spots of droppings, rusty stains on sheets, and empty shed skins. On fabric, the dark spots can bleed into the cloth the way a marker dot would.^11,18 See our full guide to signs of bed bugs.

How Can You Tell Male and Female Bed Bugs Apart?

From above, the easiest way to tell them apart is the tip of the abdomen. Females have a rounded abdomen; males have a pointed tip.^8,13,9

Bed bugs mate in an unusual way: the male pierces the female's body wall to inseminate her.^8,17 In a Virginia Tech study, females kept with males and mated repeatedly laid fewer eggs than females mated only once.¹⁹

Whatever its sex, finding even one bed bug is reason to inspect thoroughly. A single mated female can start an infestation on her own.^17,20

What Is the Tropical Bed Bug?

The common bed bug is the species found throughout the United States.^21,22 Its tropical cousin, Cimex hemipterus, is the main species near the equator.^8,7 In 2015, tropical bed bugs were found in a Florida home, the first published report of the species in the state in more than 60 years.^21,23 They have also been confirmed in Hawaii.²⁴

The two look nearly identical. The difference is the shape of the shield behind the head, which is wider with flared edges on the common bed bug, and you need magnification to see it.^8,21,22 Tropical bed bugs are highly resistant to insecticides, so a professional ID matters if you live in Florida or Hawaii.²⁴

What Bugs Look Like Bed Bugs?

Bed bugs are sometimes mistaken for ticks, cockroaches and carpet beetles.³ Here are the quickest ways to tell the common look-alikes apart:

Cockroach eggs look nothing like bed bug eggs. A German cockroach lays a brown, purse-shaped egg case about 1/4 to 1/3 inch long that holds 30 to 40 eggs.^33,34 Bed bug eggs are separate, loose eggs about 1 mm long, laid a few a day.^1,3,7 For more side-by-side photos, see our guide to bugs that look like bed bugs.

Found a Bed Bug? What to Do Next

Don't panic, and don't spend money on treatment until you know what you're dealing with. Get the bug identified first:

1. Save the bug. Drop it into a small, leak-proof vial or pill bottle of rubbing alcohol.^6,35 Don't tape it to paper; some labs won't accept it that way.⁶ If you have no alcohol, seal it in a zip-top bag and freeze it overnight to kill it. Cornell's insect lab asks for bed bugs to be frozen this way before they're mailed.³⁶
2. Take a clear, close-up photo from several angles, measure the bug or note its length (size is hard to judge from a photo), and write down where and when you found it.^35,37,6
3. Send it to an expert. Your county Cooperative Extension office can identify insects or tell you where to send them. University labs such as the Cornell Insect Diagnostic Laboratory also accept samples and photos for a fee.^10,36
4. Or call a professional. A licensed pest control company can identify the bug and inspect your home.³

While you wait for an answer, inspect your bed and furniture for droppings, eggs and shed skins. If it's confirmed, our guide on how to get rid of bed bugs walks you through treatment options, from do-it-yourself steps to hiring an exterminator.