Everything You Wanted To Know About Bed Bugs

Let's be clear, bed bugs: Nobody likes you. While you don't spread disease as far as we know, your lifestyle of biting humans while they sleep makes you our sworn enemy. But along with despising you, we have to kind of admire the persistence of you plucky little pests.

And bed bugs are indeed bugs — that's not a misnomer like "ringworm." In fact, that's why they're technically called "bed bugs" and not "bedbugs. While the one-word name is one you'll find in the dictionary, the two-word version is more scientific. Entomologists say bed bugs are "true bugs," that is, they're in the group of insects that's given the name "bug" by science. When an insect's common name is accurate in that way, it's spelled as two words, according to the Entomological Society of America. Think: honey bee, house fly, and yes, bed bug. Conversely, an inaccurate name is often spelled as one word. A dragonfly, for example, isn't actually in the fly family.

Whatever you call them, though, they've been cohabiting with us since we lived together in caves. They're mentioned in ancient Greek literature, the Talmud, and the New Testament, according to the UC Riverside Center for Invasive Species Research. In the early 20^th century, it seemed like we could finally be rid of 'em. But danged if bed bugs didn't develop resistance to our modern pesticides, and bounce back stronger than ever. Well played, you creepy little bloodsuckers. Here's everything else you need to know about these bed-dwelling critters.

Since bed bugs themselves can be hard to spot — they basically come out of hiding to feed on you in your sleep, then retreat to their lair after 4 to 12 minutes — often their bites are what people notice first, according to the American Academy of Dermatology. But it's not always easy to tell when exactly the bed bugs bite. You won't feel it when it happens because, for one thing, you're sleeping and secondly, the bugs release a substance that blocks the sensation (via American Camp Association). Even after the fact, some people don't notice the bite(s). Some people develop a reaction immediately; in other cases, it takes a few days for a red, itchy welt to appear. If you're bitten repeatedly, your body may become more sensitive, causing the reaction to happen more quickly.

Bed bug bites don't look all that different from other common insect bites. "Clues that can suggest the presence of bed bugs include finding red, itchy bites upon awakening — especially if the bites line up in a row on the skin," Dr. Jorge Parada, medical director of infection control for the Loyola University Health System, told Newswise. They can also appear in a zigzag pattern and tend to appear on areas of your skin that were exposed during sleep. The bites can take weeks to heal, but generally don't require any special treatment, Dr. Parada added. Over-the-counter or prescription creams can help with the itch.

It seemed like we had bed bugs on the run. In the middle of the last century, incidences of bed bug infestation dropped significantly, at least in developed countries. Modern science had given us pesticides that seemed capable of putting our ancient foes out of action for good. But then, as the 20^th century turned, those creepy-crawly little creeps made a comeback. By 2010, 95% of pest management companies in the U.S. reported encountering a bed bug infestation in the previous year, compared to 25% in 2000 (via American Academy of Family Physicians).

A big reason for the resurgence: The bugs developed resistance to the pesticides we'd been using to kill them. In fact, one study published in Scientific Reports determined that bed bugs have at least 14 different genes that can protect them from pesticides. These genes do everything from breaking down toxic chemicals to preventing pesticides from attaching to their target. Another study found that some bed bugs have a cuticle (shell) that's 16% thicker, protecting them from pesticides that felled their thinner-skinned cohorts.

Bed bugs are good at hiding. If you're wondering whether they're hiding in your bed, or your walls, or the chair you're sitting in right now, one way to find out is to take advantage of their weakness: They are not good at climbing smooth surfaces. That's the principle behind what's called a bed bug interceptor trap. Essentially, it's a container that bed bugs climb into when they make their nighttime creep from their hiding spots for a fresh meal (you). Once in the trap, the smooth walls prevent them from escaping. And you can make one yourself, with instructions from the University of Florida Institute of Food and Agricultural Sciences.

The idea is to place a small plastic container, like a food storage container, in the center of a large container, lids off. Then place the trap under the leg of a suspect couch, chair, or bed. (You'll want multiple traps to cover all four legs.) Bugs trying to climb onto the furniture, or climbing down off the furniture, will be able to get into the trap via strategically placed strips of masking tape. And then they'll find themselves trapped in the space between the inner and outer containers, unable to climb out. If you try it, be sure to move the furniture away from any walls, and don't let bedding touch the floor, so the critters don't have any other route to follow.

Yup, bed bugs are gross. But their presence doesn't have anything to do with the cleanliness of the environment they're in. Bed bugs can be found in developing and developed nations, in 5-star hotels and resorts, in cruise ships and apartments — basically anywhere that humans bed down. They tend to live within 8 feet of a place where people sleep according to the Centers for Disease Control and Prevention.

They like us! More specifically, they like our smell. So much so that, according to one study, bed bugs are attracted to the scent of our used clothes. Researchers placed a bag of laundered or recently worn clothing into identical temperature-controlled rooms and released ten bed bugs into each room. Four days later, the bugs were twice as likely to be found on the soiled laundry than the clean clothes, explained the University of Sheffield.

According to the researchers, bed bugs can detect 104 different chemicals released in the human scent. Some of these are likely left behind in clothing after it's been worn, and so they attract the bugs. This may be one way that bed bugs spread across long distances. They find their way into soiled laundry in, say, a hotel room, and hitchhike in a suitcase or laundry bag to a new home.

Believe it or not, some insects, bed bugs included, can see color. This might seem of limited use for bugs that come out at night, but they sometimes seek hiding places when it's light out. It turns out that color plays a role for bed bugs looking for a place to hide. As part of a study published in the Journal of Medical Entomology, researchers tested this by placing bed bugs in a petri dish that contained folded cards of various hues, then recording which of these "harborages" the bugs moved to over the course of 10 minutes.

The insects showed a preference for hiding under red and black cards, possibly because both colors are dark to their vision. And since bed bugs are red, that color might suggest other bed bugs are present (bed bugs live in groups). Sex affects this preference, though; female bed bugs preferred lilac or violet harborages. Yellow and green harborages were the least preferred colors; they actually seemed to repel the bugs. These colors might be avoided because they suggest a brightly lit area. A similar dislike for green and yellow has been found among mosquitoes and houseflies. But before you go out and buy new yellow sheets, keep in mind that these color preferences were related to bed bugs seeking shelter, not looking for their next meal.

While there are an array of methods (of varying effectiveness) available for dealing with bed bug infestations, one especially useful tool to keep them in check is legislation. An analysis using U.S. Census data and other statistics examined the impact of laws requiring landlords to disclose bed bug infestations. The researchers not only found that these laws reduce infestation rates, but over time they also lead to cost savings for both landlords and tenants.

Disclosing an infestation initially costs landlords money because it results in vacancies and the expense of eliminating the bugs. But within five years, landlords come out ahead since treatment prevents the bed bugs from infecting other rental units. Plus, the bug-free properties experience less turnover of tenants. Renters also save money when these laws are in place since they don't have to replace infected furniture or move out.

According to the researchers, this type of legislation can be an important arrow in the anti-BB quiver. "Our work suggests that while it can be extremely difficult to eliminate bed bugs from homes, it might not be so difficult to eliminate them from cities," study author and epidemiologist Michael Z. Levy said in a press release.

Dealing with a bed bug infestation may cause subsequent mental health effects, including insomnia, nightmares, and even flashbacks, according to a study published in The American Journal of Medicine. However, a comprehensive analysis of bed bug data found that more research is needed to establish the true scope of this problem.

It seems that the bugs can also leave behind physical traces after they've been eradicated. Their feces contain histamine, a chemical that can trigger an allergic reaction when ingested. For some background: Our immune systems also make histamine to cause sneezing, tearing, and other reactions to eject allergens from our bodies.

Researchers sampled house dust from 29 apartments, some of which were infested with bed bugs, in which case dust was collected before and after treatment. Homes that had no bed bug presence showed only traced amounts of histamine in the dust, but levels were high where bed bugs were present. And they stayed high even three months after bed bugs had been eliminated. Histamine can provoke allergic responses and asthma, the researchers said, so bed bugs might trigger allergies in a manner similar to cockroaches and dust mites, even after they're gone from the premises.

Bed bugs often get a negative connotation. Many people believe they tend to hide out in unclean or unsanitary homes. In reality, the EPA says that bed bugs aren't necessarily drawn to dirt and ick. Instead, clutter simply makes it easier for them to hide than in a mess-free zone. Bed bugs will still make their way into clean and tidy homes if they feel like it will become a safe haven for their colony.

In addition to blood, bed bugs are attracted to warm spaces. Of course, cluttered areas tend to make for a cozy, warm spot for their families. What else produces heat? Bodies, of course, especially when they're sleeping. This is one reason why bed bugs tend to congregate around beds and hide in mattresses. Another reason is that they like carbon dioxide, which humans produce when they breathe out air. The mixture of breathing and heat release as you sleep is much more welcoming for a bed bug family than a dirty home.

Why do some homes and places get bed bugs, while others can spend a lifetime never experiencing a bed bug infestation? Some places are simply more susceptible to hosting bed bugs than other places. For instance, signs of bed bugs are notoriously spotted at hotels because of the number of travelers that pass through. While bed bugs don't typically cling to humans, they certainly can hide in clothing or luggage, joining a traveler on their trip and making their hotel room their new home.

Similarly, daycares and schools can also become home to bed bugs hiding in backpacks or clothing. And it's not entirely uncommon for bed bugs to transfer from one place to another by hitching a ride with social workers and emergency personnel, like police officers or firefighters, who might enter several homes or businesses each day. Medical facilities and office buildings could also find bed bugs more commonly than other places without as many people in and out each day, putting their workers at risk of bringing a few back to their homes.