Before trying to figure out if you have a bed bug infestation, you need to understand what bed bugs look like. It’s easy to mistake a bed bug for a tick or carpet beetle—it’s not like you want to get that close to a bug you want to squash and kill.
What do bed bugs look like?
Bed bugs—or as entomologists call them, Cimex lectularius—are small, brownish-red, with a flattened oval-shape body and visible body segments. Younger ones appear as a pale yellow. By the way, if you spot what you think is a bed bug, don’t kill it. Capture it and seal it in a container so it can be identified. Here are 16 secrets about bed bugs that help you keep them out of your house.
How big are bed bugs?
Adult bugs average around five millimeters (picture an apple seed) long and have a broad-shaped oval body that is flat and brownish to reddish brown. Bed bugs have two antennae, six legs, and an abdomen with 11 sections that expand when they take a blood meal. The tips of the abdomen are usually pointed in males and more rounded in females. Don’t fall for the myth that the bugs are microscopic—or any of these other common bed bug myths.
How big can bed bugs get?

Bed bugs are pretty uniform in size, though that size changes dramatically throughout their six- to 12-month lifespan. A baby bed bug, known as a nymph or instar, goes through five growth stages before reaching bed bug adulthood. Bed bugs also expand and change color after they gorge on you—see for yourself with our full guide to what bed bugs look like.
What do bed bugs look like after feeding?
Bed bugs sport a flat and oval shape by day, but once they get a blood meal, their body expands and looks like a mini red torpedo. This bed bug is so full, it’s leaking the extra in a trail of blood behind it. But they don’t need to feed every day—usually, it is every three to seven days, says Dini M. Miller, Ph.D., department of entomology, at Virginia Tech. There’s the digestion state too, in which the bed bug returns to the oval shape of the unfed stage but has a black spot on its body, which is the digested blood that it will excrete later.
When are bed bugs active?
Bed bugs are cryptic and pretty much hide out during the day in cracks and crevices with other bed bugs in harborages (bed bug community) hoping to remain undiscovered, explains Dr. Miller. However, once midnight rolls around, the party starts for the hungry bed bugs which remain active until about 5:00 a.m. The timing couldn’t be more perfect for them because those five hours are when most people are in a deep sleep.
How do bed bugs find us at night?
Bed bugs don’t need a neon vacancy sign flashing from our toes to let them know where we are, but the cues scientists think they use are pretty fascinating. “They can become alerted to the presence of a food source in a room because we emit carbon dioxide, which stimulates them,” says Eric Braun, a board-certified entomologist for Rentokil Steritech, a pest control company. “They also look for the heat signature from our bodies to find us.” Still, bed bugs have to be within close proximity to sense us—usually five to 20 feet from their harborage.
How do bed bugs bite us?
Look closely at this bed bug picture and you’ll see the mouthparts bed bugs use to probe our skin. They’re pretty choosy and may poke our skin several times before they find a capillary space that allows the blood to flow quickly into their bodies. That means we could wake up with several bites from one bug, Dr. Miller says. Once the bed bug settles on a location, it will feed for about five to ten minutes. When its belly is full, it will return to the crack or crevice where other bed bugs are hanging out. Here’s how to treat the most common bug bites, including bed bugs.
Will I see a bunch of bed bugs together?
“Unlike bees or ants, bed bugs don’t exhibit social or task-related behaviors. They will harbor in clusters and groups, finding one another through the use of an aggregate pheromone, but they are not a true colony,” says Braun. Basically, bed bugs go about their day, driven by their own needs and they don’t come out all at once as a group to feed on a host.
Why do some bed bugs have a black spot on them?
Dr. Miller says the black part is the digested blood the bed bugs ate a couple of days ago. Given bed bugs don’t feed every day, most of the bed bugs are in the digesting state and not feeding. They’ll excrete the digested blood later which will be evident to us as dark spots (feces) in cracks and crevices or seams of furniture.
How do bed bugs multiply?
At first glance, this bed bug picture looks kind of cute—two bed bugs in a warm embrace. But in reality, the male is actually mating with the female by stabbing her in the side rather than mating with her in her genital area. “He pushes his paramere through her body wall. She does kind of have a receptacle for his parameter called the spermalege. But he still wounds her in the process of ‘traumatic insemination,'” says Dr. Miller. The female must heal from the wound but it does leave a scar. And if she’s been mated one too many times, she’ll leave the aggregate to avoid further abuse, Dr. Miller says.
What do bed bug eggs look like?
Once a female has sucked down a full blood meal, she’s ready to lay some eggs. In fact, she can lay one to seven eggs per day in a ten day period. But she can’t lay eggs on an empty stomach, which means she’ll need to feed again to produce more eggs. The eggs are clear and tubular, similar to the shape of a jelly bean but in reality the size of a speck of dust. As fragile as they appear, they have a pretty good shot at hatching; Dr. Miller says 97 percent will hatch under optimal conditions.
Where do bed bugs lay eggs?
The female bed bug lays her eggs singly or in groups and just about anywhere in a room she wants, but it won’t be on your body. Bed bugs prefer quiet places since they are shy. The eggs are sticky when they pop out and as this bed bug picture shows, one got stuck on the back of bed bug. It’s worth mentioning that a single mated female brought into your home (via a mode of transit like a purse, duffel bag, blanket, etc.) can cause an infestation from the eggs she will lay in your house. Follow these steps to avoid an infestation.
How long does it take for bed bug eggs to hatch?
In Dr. Miller’s lab, 60 percent of the eggs hatch at six days old when temperatures were greater than 70° Fahrenheit and 90 percent will have hatched by the eighth or ninth day. Hatching time takes longer when the temperatures drop. When the conditions are ideal, a bed bug population can double every 16 days.
What do bed bugs look like when they are born?
You would probably need a magnifying glass to see a newborn bed bug as they are super tiny, about the size of a pinhead. They are translucent with red eyes as seen under the microscope in the bed bug picture. It won’t take too much time for them to go through all five nymphal stages and become a reproductive adult. As long as they get their first blood meal within about 20 days (and don’t get crushed or die from something else), they’ll become a full-fledged adult in about 37 days.
What happens after bed bugs drink blood?
These two nymphs just finished feeding and have a full blood meal in their body. Seems like they’re comparing notes on their dinner but once they’ve gone through all five growth stages and become adults, they’ll trade blood meal reviews for mating time. It’s not uncommon for bed bugs to get frisky after a full blood meal, especially the males.
How many baby bed bugs survive after hatching?
Fresh out of the egg, bed bugs are pretty fragile but they do come from a hardy species so they have genetics going for them. But still, Dr. Miller says newly hatched nymphs are exceptionally tiny and can’t travel great distances to find a host for a blood meal. And if the momma laid her egg too far from the host, the nymph could die of dehydration before sucking down its first blood meal.
Do bed bugs eat other things besides blood?
Blood is the only food source bed bugs need to survive. And a human host is their first choice. We’re just easier for bed bugs to crawl on than an animal or bird. Getting enough blood is essential for a bed bug to survive though. This nymph is so young it still has some of its egg cap on and didn’t get a full blood meal yet. You can tell because she has more storage available. If a bed bug doesn’t get enough, it will likely die of dehydration Dr. Miller says.
Where do bed bugs live?
They gravitate toward places humans don’t notice on a daily basis—the edge of wall-to-wall carpeting, in seams of furniture, behind wall-mounted fixtures, in piles of clutter and clothing in closets and light switch plates. Staying out of sight isn’t the only reason though. “Bed bugs pack themselves so tightly into small cracks and crevices so they can maintain a microhabitat of favorable temperature and humidity, thus increasing their ability to survive periods of starvation,” says Dr. Miller.
Why do some bed bugs have different shapes?
Depending on the growth stage, one bed bug may be bigger than another and what a bed bug look likes after a blood meal coincides with that stage. This bed bug picture shows bed bugs at different growth stages. Regardless of age, their shape transforms by becoming more narrow and longer than their usual flat, oval-shaped body. Then, in a couple of days, when the digestion process is complete, the pre-fed dark and flat body return.
Can bed bugs get inside a mattress cover?
Unfortunately, if the mattress cover has even a tiny opening, the answer is yes. “This zipper photo shows that not all mattress encasements can keep bed bugs contained. You notice the zipper does not reach the very top of the enclosure. So bed bugs were able to come out and feed when we laid my technician’s arm across it,” says Dr. Miller. Bed bugs are all about being subtle. If you notice one of these warning signs you could have a bed bug problem.
Can I see a bed bug on my purse or backpack?
It’s difficult but not impossible to see a bed bug on a personal belonging. Adult bed bugs are easier to spot because they are larger at about three to five milliliters and reddish brown. Younger stage bed bugs are pale yellow and smaller. If you’ve been traveling, visiting several homes or buildings where people come and go, inspect your purse, backpack, or laptop bag before you bring it in the house. And whatever you do, don’t place these items near your bed without a thorough inspection.
Do bed bugs hide in our hair at night?
Some insects like lice have grasping legs that make it easier to navigate human hair and animal fur but bed bugs don’t have the same legs. “They prefer to feed on exposed areas of skin and don’t live on the body, so haven’t adapted any spines or specialized legs,” says Jody Green, PhD, an urban entomologist at the University of Nebraska-Lincoln. “I believe this is the reason they would prefer to feed on humans than other animals, but of course, in the absence of a host, they will feed on a different host.”
Do bed bugs fly?
Bed bugs can’t fly or jump like fleas nor can they sprint as fast as cockroaches but they’re not slowpokes either. They can travel across sofas or down a hall in no time. And even if it doesn’t find a human host right away, it can survive months without a blood meal before it dies of starvation—which by the way, Dr. Miller says is largely due to dehydration because bed bugs are mainly hydrated through blood when they live in an indoor environment. Now, find out the bed bug “facts” that should be exterminated for good.
What are the signs of bed bugs?
Bed bugs go to great lengths to stay out of sight, something they excel at thanks to their tiny size and flat shape. When they’re not sucking your blood—usually at night, but they can adjust to daytime sleepers—they prefer to hide in dark spaces where they can digest their meal, mate, and lay eggs. Even though you might not see the creatures, you can see evidence of them: These are the bed bug signs entomologists use.
Watch for bed bugs
If you’re sharp-eyed, you might spot the insect itself: They’re about the size of an apple seed. That’s why they creep up on you while you’re sleeping because they don’t want to be disturbed while feeding or when they are digesting their blood meal, mating or laying eggs in their harborage, hidden out of sight. They’re also quick and will scatter when you enter the room. Here’s where you can get a better sense of what bed bugs look like.
Watch for bed bug bites
A clear bed bug sign is a bite—which you’ll wake up with when they’ve been feeding on you at night. If you wake up feeling itchy and have red welts or bumps in a line or in several zig-zag clusters, that’s a good indication you’re dealing with bed bugs. The bugs have a numbing agent in their saliva so you don’t feel the bite, says Brittany Campbell, PhD, an entomologist with the National Pest Management Association (NPMA). The itching that most people feel stems from a mild allergic reaction to the numbing agent. The good news, she says, is that bed bugs are unlikely to spread disease, unlike other biting insects like mosquitoes.
Watch for bed bug poop
“Regardless of the blood source or host,” says Campbell, “once bed bugs digest their blood meal and excrete it, it appears as dark brown or black spots on a surface—very similar to what you would expect an ink stain to look-like if your pen leaked onto your clothing,” says Campbell. You might notice the spots on your sheets, mattress, box springs, or in the cracks and crevices of your headboard, nightstand, or other bedroom furniture. Other “droppings” are tiny blood spots. Sometimes bed bugs “overeat” and they excrete a few drops of blood that will appear as tiny red dots if the fabric or upholstery is a light fabric.
Watch for bed bug shells and eggs
Other bed bug signs include molted shed skins and eggs, says Campbell. “The molted skins are very thin and lighter in color but will be in the same shape as a bed bug since they are essentially the left-over skin of the bug.” You might be able to see eggs, though they are tiny—about the size of a pinhead—and whitish or translucent. Still, these are bed bug signs to look for when you check into a hotel room.
Watch for bed bug signs in other rooms
Bed bugs won’t stay in your bedroom—if you fall asleep in front of the TV on the couch or in a recliner, say, they’ll set up camp in the furniture nearby. “Bed bugs commonly infest sofas and chairs and can even hide unseen in chair legs, if the legs are hollow. The bugs will reside in any hidden crack or crevice of the sofa, including deep into the couch under the cushions, inside of the wooden structure of chairs and sofas or metal, as well as inside of screw holes and screw heads,” says Campbell. Just don’t look for the bugs in your hair—and don’t fall for these other myths about bed bugs.
Where else can I see bed bug signs?
You can find bed bug signs in curtains, walls, behind baseboards, wallpaper, picture frames, books, electrical switch plates, electronics—really, just about anywhere inside your home. They can also hitch rides: “Beg bugs are also known to survive in temporary or alternative habitats, such as in backpacks and under the seats in cars, buses, and trains,” says Campbell.
Bed Bug Eggs: Everything You Need to Know
A bed bug’s life starts as a tiny egg, barely noticeable to the human eye. But in just days, this tiny, blood-sucking insect will hatch and be searching for its next blood meal in you.
How many eggs do bed bugs lay?
Dr. Dini Millers’ research lab at Virginia Tech says the more meals the female gets, the greater the number of eggs she will produce. So, if she is able to feed every week, she could produce five to 20 eggs. But she might not get to feed every week, in which case she would produce fewer eggs. According to Dr. Miller’s research, bed bugs can lay up to 113 eggs in a lifetime, which can be around a year.
Male bed bugs get frisky after a blood meal
After female and male bed bugs get their fill of blood from you, they head back to the harborage (their home) to digest their blood feast and mate. Dr. Miller’s research tells us male bed bugs are particularly interested in mating after a blood meal. Afterward and for the next several hours, their sperm will migrate to the female’s ovaries and fertilize her eggs. Check out what bed bugs look like after they eat and when they mate.
Bed bug eggs are dropped
Bed bug eggs are cream-colored and have an elongated shape that measures a tiny one millimeter in length. The female can lay her eggs singly or in groups. “Bed bugs can ‘glue’ their egg to a surface and it can remain there until it hatches if in an undisturbed location such as a crack or crevice. They can be dislodged though, so they can be found on the floor if scraped off,” says urban entomologist Jody Green, PhD, at the University of Nebraska-Lincoln. The eggs are usually pretty safe unless a human comes along with a scraper or strong vacuum to suck them up. Vacuuming is one way to stay on top of bed bugs. Here are some other things you should be doing to keep bed bugs out.
Bed bug eggs are tough
You would think something as small and seemingly frail like a bed bug egg wouldn’t have much of a chance, yet Dr. Miller’s research says that under optimal conditions, just about 97 percent of the bed bug eggs hatch. Insecticides sold at the local hardware store can’t penetrate the protective eggshell, says Green. Even diatomaceous earth, one of the home remedies for bed bugs, only kills nymphs and adult bed bugs—not the eggs. Here’s what’s lethal to the eggs: Temperatures above 120 degrees, or below 0. Green says some professional products may be successful at wiping out the eggs but only with precise and proper application techniques.
How long does it take for bed bugs to hatch?
A new generation of bed bugs will hatch between nine and 12 days of optimal room temperatures—around 72 degrees—Green says. Hatching takes longer under cooler conditions. Once the nymphs emerge, they immediately start searching for a blood meal. “Literature has suggested that nymphs require a blood meal soon because they may desiccate. A blood meal will help them with moisture, but they can also survive by hiding out in crevices in optimal temperatures of 70 to 90 degrees,” says Green. Even without a blood snack, nymphs may live for two to four months. Check out some more secrets bed bugs don’t want you to know.