Sandy McDonald is 48 years old, a former hospital phlebotomist now receiving disability due to a herniated disc at the base of her skull. Until recently, she and the youngest of her three daughters, who's seventeen, lived in a garden-level two-bedroom apartment in the Montclair neighborhood. From the outside, the apartment complex is handsome. Advertised as offering "a luxury lifestyle at an affordable price," its two-tone buildings resemble ski lodges. But inside, McDonald's apartment was unremarkable: beige carpeting, white walls and a tiny shotgun kitchen with a leaky dishwasher.

And, starting in June of last year, bedbugs.

The first bite McDonald noticed was on the top of her left foot. It was big, puffy and purple-ish. It itched twice as bad as a mosquito bite, and before long, it began to ooze. McDonald thought it was a spider bite; she'd been bitten once by a brown recluse in Arkansas, where she'd grown up. She'd reacted severely to that bite and figured this might be the same thing. "I waited a while and I tried to pamper it," McDonald says. But it didn't get any better. Soon, oozing welts were creeping up her left leg and onto her back.

Eight months later, the pattern of bites is still discernable. She pushes up the sleeves of her snowflake pajamas to reveal dark black circles that dot her arms like paint splatters. There are more on her shins, neck and chest. Sliding her left foot out of a well-worn navy-blue slipper, she points to the scar of the bite that started it all.

"I finally decided I needed to go to the doctor," says McDonald, who has since moved to a different apartment. Her doctor diagnosed her with shingles, a blistering skin rash that generally affects one side of the body, and prescribed her an antibiotic. She took the entire dose, but her bites didn't fade. So she saw another doctor, who said it was a skin infection and prescribed ointment.

When that didn't work either, her doctor asked if McDonald might have bedbugs. She hadn't seen any bugs or felt any bites, so she said no. "This was the first time the word 'bedbugs' had been mentioned," she says.

The second time came soon after. McDonald's sister had been hanging out at McDonald's apartment every day and began getting red bites on her body. McDonald says her sister figured they were mosquito bites, but she made a doctor's appointment to be sure. The bites weren't from mosquitoes, the doctor said. They were from bedbugs.

McDonald panicked. She called the apartment manager and asked for an exterminator. But she says she was told it would be two weeks. By that time, McDonald says, "I'm looking horrible. I'm looking like an AIDS-infested, ate-up person." She couldn't eat. And she certainly couldn't sleep. She started camping out on her couch and conducting middle-of-the-night bedbug raids in her bedroom, snatching off her sheets and inspecting every inch of her mattress and box spring for insects. She didn't find anything.

In late summer, an exterminator finally came to her apartment. With a high-powered flashlight, he searched her darkened bedroom for bedbugs but found nothing. "At this point, I just want to die," McDonald says.

She made an appointment with a dermatologist and implored the company that managed her apartment complex to hire another exterminator for a second opinion. They did, and that exterminator found what the other hadn't: a single bedbug.

"When the guy showed me the one bedbug, I immediately felt like there were a million tiny bugs all over me," McDonald says. "I cried."

Despite McDonald's uncommonly severe reaction to the bites, the exterminator determined that it was a mild infestation, and the management company paid for the spraying. "We take seriously any pest-control complaints we receive," says Brenda Wright, vice president of Utah-based Apartment Management Consultants, which runs 39 properties in Colorado, including the one where McDonald lived, in an e-mail. "We investigate those complaints immediately and act quickly to remediate the issue when warranted. If it is determined that a pest-control issue is valid, we immediately contact an exterminator."

But a few weeks after the exterminator sprayed, McDonald says she saw another bedbug crawling on the side of her king-sized mattress. She asked the manager to schedule another spraying; when they hesitated, she called the city's 311 Help Center.

Denver's bedbug infestation is said to be one of the worst in the nation. Last summer, pest-control giant Terminix ranked the city's problem No. 6 in the country based on the volume of calls to its offices. Meanwhile, Orkin ranked Denver No. 4, behind only Chicago and the Ohio cities of Columbus and Cincinnati. By Orkin's calculation, New York City -- commonly thought of as the bastion of the modern-day bedbug -- was No. 7.

Denver doesn't keep its own statistics. But the city's housing code requires apartment owners and operators to keep their premises free of insects. If a tenant thinks a landlord is being delinquent, the tenant can complain to the city's Department of Environmental Health, which will send one of its four inspectors to investigate. The potential punishments are meek -- a citation and, rarely, a fine -- but records reveal that just the threat is often enough to make landlords (and tenants who'd rather live with vermin than let an exterminator through the door) comply with the code.

The complaints also provide a snapshot of the city's bedbug problem. A review of city records by Westword found 305 complaints about bedbugs in 2010. Many were from residents of apartment buildings, reporting infestations. Fewer complaints came from guests of hotels and homeless shelters. A handful of callers reported infestations in Denver gyms, stores and single-family homes.

One of the complaints was McDonald's. Two days after she called, a city housing inspector came out to look. He didn't find any bedbugs, but he did make sure that the manager scheduled a follow-up spraying.

"Once I called that 311, it was like clockwork," McDonald says.

******

Karl Schiemann oversees the city's housing inspectors. At 46, he's tall, with Anderson Cooper-ish gray hair and blue eyes. A former chef, Schiemann became a food inspector sixteen years ago before switching to housing in 2007. It's the city's only complaint-driven inspection division, and because of that, Schiemann likes to repeat a saying: "There's your story and there's my story, and the truth lies somewhere in the middle."

The complaint process works like this: A tenant calls 311 and is connected with a department intake worker who notes the caller's vital information: name, address, phone number. Then, in a sort of choppy shorthand, the intake worker documents the complaint:

"Bed bugs. Clr threw away all beds and bedding. Now couch is full of them."

"Bed bugs. Management refuses to spray."

"Bed bugs. Clr states manager is aware but can't do anything more to help. Clr has had to sleep in her car to avoid getting bit."

Within a day or two, the complaint is assigned to one of four inspectors, who makes an appointment to visit the property and look for the telltale signs of an infestation. For bedbugs, that means blood spots on sheets, tiny black dots of fecal matter clustered on the edges of mattresses, piles of translucent skins that the bedbugs shed like snakes, white eggs the size of dust specks, and, of course, bedbugs themselves, which are brownish-red, flat, and about as big as an apple seed.

Bedbugs feed solely on the blood of animals -- humans, most often -- but since they're not known to transmit disease, their biggest downside may be the ick factor.

The inspector uses a one-page form to document by hand what he or she finds. A typical entry looks like this: "3/18/10: Tenant at home. Provided and discussed bed bug pamphlet. Tenant said found about 4 bed bugs and informed management and was told pest control company due this afternoon. No sign of bed bugs. Spoke with property manager. She confirmed that American Pest Control will be servicing unit today."

Most bedbug complaints are "unsubstantiated," which is one of three possible outcomes. The others are founded and unfounded. Only a founded complaint will trigger a citation, and if that doesn't work, a summons to court, where a judge can impose a fine on a landlord or an ornery tenant who blocks attempts at extermination. But court appearances are rare, Schiemann says. Most cases -- even unsubstantiated ones -- are closed after the property manager assures the inspector that a spraying has been scheduled.

Of the 28 complaints Westword investigated closely, seventeen were unsubstantiated. But that doesn't necessarily mean the caller didn't have bedbugs. It's because proving a bedbug infestation is harder than proving other complaints.

"They're so small," Schiemann says. "This one case I had, the lady thought she was going crazy. 'Pest control is out here, says I don't have any. Management isn't going to treat my property. But I'm just covered in bites.'...When she and I finally tore her bed completely apart, we found them." But ripping apart furniture is an exception. In cases where a tenant has evidence of bedbugs, he explains, "I don't go digging too much." (Schiemann says neither he nor any of his inspectors have ever brought bedbugs home with them. But he also doesn't make a habit of rolling around on infested beds or lounging on couches.)

On a recent inspection of a neat, one-story brick house located on a quiet Denver street, Schiemann showed up around the same time as the Terminix man. Both men, armed with flashlights, poked around the owner's waterbed in search of evidence.

The daughter of the 71-year-old man who lives there didn't want the location of the house or her father's name used in this story, though her father allowed Westword to tag along to the inspection. "He wanted to let people know it happens to the cleanest of people," she said of her father's infestation. "He wanted to help."

******

Melinda Covington coaxes a bedbug onto her left forearm -- the underside, where it's nice and smooth, because bedbugs don't like to navigate hair. The brown bug waddles around for a few seconds before settling on a spot in the middle of her arm, about a ruler's length from her manicured fingernails.

"He's feeding," she says.

"Yeah, his butt will go up and he'll kind of start trying to pump and work it a little bit," adds Jason Zetwick, operations director for BedBug Blasters, a company that Melinda and her husband, Chris, started a few months ago in Westminster that eliminates bedbugs with heat treatments. "So, notice his size right now. And then here in about five minutes, he's going to double in size and turn bright, bright red."

Looking closely, it's possible to see where the bedbug's straw-like mouth part is inserted into Melinda's skin. But she can't feel a thing. That's because bedbugs inject their victims with a numbing agent that dulls the pain of being feasted upon.

Heat treatment is pesticide-free and doesn't require a license. The science behind it is that bedbugs can't withstand temperatures above 120 degrees. So instead of using chemicals, none of which are 100 percent effective, companies have begun offering to essentially turn bug-ridden apartments into ovens and bake the bedbugs to death. (According to John Scott, the pesticides program manager for the Colorado Department of Agriculture, 57 new residential and commercial pest-control companies have opened in the state in the past three years, bringing the total to 176. That's a 45 percent increase.)

"It only takes one minute at 122 degrees for a bedbug to die," Chris Covington says. For years, the Covingtons have owned two other companies: Purple Penguin Carpet Cleaning and Rapid Restoration, which provides services that range from drying flooded homes to removing raw sewage and cleaning up meth labs. He says they decided to start BedBug Blasters after realizing that the heaters they use to dry out flooded structures were the same ones being used to kill bedbugs through heat treatment.

And to make sure all the bugs are obliterated, the BedBug Blasters crew will walk their new bedbug-sniffing dog, Bugsy, through a treated apartment two days later. Bugsy is a rescued beagle puppy trained at the National Entomology Scent Detection Canine Academy in Florida; detection dogs are 98 percent accurate at finding live bedbugs, according to a 2008 study by the University of Florida. Humans are much less accurate.

To train Bugsy, the Covingtons keep a passel of live bedbugs, which need to be fed regularly, in a glass container that resembles a salt shaker but with smaller holes on top. Like a K9, Bugsy is a working dog; he only gets fed by his handlers, Chris Covington and Zetwick, and only if he "finds his Bs," the command for sniffing bedbugs. To keep Bugsy sharp, the men practice with him several times a day.

On a recent morning, Zetwick, a bearded 33-year-old who grew up duck hunting with Labrador retrievers, prepares for a practice "hide." He straps on a fanny pack full of kibble and puts Bugsy on a leash. "You ready to go to work?!" he croons in an excited tone that's part schoolteacher, part baby talk. "Let's find the Bs! Let's find the Bs!"

Bugsy begins sniffing as Zetwick leads him counter-clockwise around one of the offices in the industrial park where BedBug Blasters is located. Bugsy soon begins scratching at a filing cabinet, signaling to Zetwick that he smells bedbugs. Zetwick opens a drawer and pulls out a vial of live ones.

"Good! Goo' boy!" he squeals.

Innovation isn't cheap, however. Heat treatment starts at around $700 and can run up to several thousand dollars. Treating with pesticides generally costs less, though not always. For a lower fee -- $350 for up to six units -- BedBug Blasters will certify that an apartment is clean before anyone moves in. It's protection for the landlord, Chris Covington explains. "What we're saying to them is, have us walk Bugsy through the apartment and we can certify that it's bedbug-free. Then you can wash your hands of it."

At least for a while.

Bedbugs are wily creatures. Around for hundreds of years, they were practically eliminated in the 1940s and '50s due to the widespread use of DDT. But they've returned with a vengeance in the 21st century. Hearty as hell, a bedbug can survive for an entire year without a blood meal. They're also quick and efficient reproducers: A female can lay up to 500 eggs in her lifetime. That's why pest-control operators often say that a bedbug infestation is defined as one pregnant female.

Bedbugs are easily spread. Though they can't fly or jump, they're excellent hitchhikers. "You could sit on a public bus and get bedbugs," says Michele Evans, the owner of Anchor Pest Control Services in Denver, an extermination business started by her dad eighteen years ago that offers both heat treatment and chemical treatment.

"It doesn't matter who you are," she says. "You could be poor as poor or rich as rich. It's economically blind."

In the past five years, Evans says the number of bedbug infestations her company has treated has grown exponentially. "It's endless," she says. "We've found them in pieces of luggage. We've found them in drapes. We've found them behind wallpaper." She tells the story of one woman who had such a bad infestation that they found bedbug skins in a jewelry box stashed in the top of her closet. She hadn't opened the box for ten years, but the bugs somehow found their way inside.

"Bedbugs are going to be here," Evans adds. "If you don't know somebody today who has them, it's guaranteed that in the next year, you will."

******

The landlord sits at a table in the back of a charming coffee shop in upscale Larimer Square. Dressed in crisp business attire, he's nervous. He will talk to Westword only on the condition of anonymity. "It's just bad PR to have your name associated with a bedbug story," he explains, and this man's name is associated with several thousand units.

Bedbugs started making themselves at home in his buildings about three years ago. Since then, he's spent gobs of money trying to eradicate them, using chemicals, heat treatments and dogs. "It comes down to hand-to-hand combat with those suckers," he says. But time and again, his efforts fail because the tenants don't do their part to stop the problem, he explains. They continue to dumpster-dive and pick up secondhand furniture. They're not vigilant about washing and drying their clothes at hot temperatures, and they don't vacuum and clean their apartments as required prior to extermination.

"The residents feel like victims because they have all these bedbugs," the landlord says, "but we're the ones taking care of it."

The city's housing code puts the onus on both the owner and the occupant. In the section titled "Extermination," it says that occupants shall maintain their dwellings free of insects. But the question of responsibility gets trickier in a multi-unit building. In that case, the code says that the occupant is responsible for extermination if their unit is "the unit primarily infested." In a case where two or more units are infested, extermination is the responsibility of "every owner and every operator" -- not the occupant.

Of the 305 bedbug complaints recorded in Denver in 2010, most of the repeat offenders -- properties with more than three complaints -- were multi-unit apartment buildings. The pattern could be chalked up to simple math: More units equals more chances for complaints. Or it could be that bedbugs spread more easily in big buildings. Attracted to the carbon dioxide humans exhale during sleep, bedbugs who have lost their food source (perhaps because someone moved out) will seek a new one next door.

Viviana Aguilar manages a 660-unit apartment complex in northeast Denver. Last year, the complex was the subject of six complaints from five different residents; one woman filed two complaints, four months apart. Her second complaint was recorded as this: "Bed bugs. Threw away children's beds. Sprayed twice but still present. Tried everything on her own to get rid of them herself. Caller 6mos pregnant."

Aguilar says the apartment complex bears the cost of extermination, which she estimates at about $2,000 a month. For years, she only sprayed apartments whose residents complained. But after countless sprayings and re-sprayings, she found that method wasn't working. Inevitably, there'd be one resident who didn't mind living with bedbugs or who didn't want to bother with the elaborate pre-spraying preparation. Even if they rid the rest of the building of pests, that one untreated apartment would cause another widespread infestation. "It all depends on how your neighbor lives," she says.

As of January 1, the complex has imposed a mandatory extermination policy, meaning that every single unit in all 64 buildings -- no exceptions -- will be treated, Aguilar says. Residents are given notice of when their apartment will be treated and assessed a $75 fine if they don't follow preparation instructions.

"We won't get rid of the problem on one treatment," she says. "But at least we're going into every single unit and making sure it's not a sanitary problem. If it is, we take care of it by making sure the resident cleans up."

Don Brennan, a partner at Denver-based Pinnacle Real Estate Management, says his company took a more aggressive approach. In July, Pinnacle assumed management of a 33-unit apartment building in Capitol Hill that was the subject of five complaints last year. One of the complaints was from Paul Farris, a 59-year-old former gardener who says he was once the assistant manager of the building. The company that managed the building before Pinnacle refused to thoroughly spray for bedbugs, Farris says. "You cannot spray just one apartment...and think you're going to get rid of them. If you spray one area, they span out. If you try to do a checkerboard, they go to the places where it hasn't been sprayed."

Farris figures he picked up the bugs from his neighbors. As part of his job, he was constantly in and out of apartments, fixing leaky faucets and squeaky doors. The infestation was bad, he says. One of the residents, an older military veteran who was often hospitalized for diabetes, had a futon that was crawling with bugs. Farris describes a pouch on the underside of the futon, which was for storing the futon's detachable wooden feet. "You open up that pouch and there were so many bedbugs that started coming out, it was like an invasion force hitting the beach in Normandy," he says.

In June, several residents called the city to complain. A city inspector determined that the complaints were founded and ordered the landlord to take care of it. "There is a bed bug infestation within this dwelling structure," the inspector wrote in a letter. "Live bed bugs were observed in units 108 and 109. Unit 104 is self-treating, 308 complained of bites, and 310 tenant provided numerous dead bed bugs in a pill bottle."

That month, the building owners fired the old management company and hired Pinnacle, which spent $5,745 on extermination over a six-month period. But not without some heartache: Residents who refused to comply with mandatory spraying were evicted. "Most people don't want to live in an environment where it's dirty and there are bedbugs," Brennan says. "The people who do usually aren't your best tenants. We had to go through the process of moving people out who didn't want to deal with the problem."

Now, Brennan says, the building has "a large percentage of new tenants." As for Pinnacle's policy regarding bedbug disclosure, he says, "If someone asked if the building had bedbugs, we would tell them. We'd also tell them, 'Here's what we've done to resolve the problem in the building.'"

But total honesty can be bad for business. As the clandestine landlord in the coffee shop more delicately pointed out, nobody wants to live in a place that they know was once crawling with armies of bloodsucking bugs.

******

Nobody except, perhaps, Bob Hancock, Denver's own bedbug researcher.

A 46-year-old biology professor at Metropolitan State College, Hancock describes himself on the jacket of his self-made documentary, "Mosquito Man: The Bedbugs of London," as a "filmmaker, entomologist and dynamo." Bald, fit and friendly, he rattles off facts about bedbugs with the excitement of a scientist and the patience of a teacher. Bedbugs aren't nocturnal, he'll tell you. They just don't like light.

Fascinated with bloodsucking insects since he was a child growing up in Scottsbluff, Nebraska, he eventually went to graduate school to study entomology. There he had a professor who was obsessed with bedbugs. One day, Hancock walked into his professor's office to find him with his pant leg rolled up and a colony of bedbugs Velcroed to his thigh, feeding.

Today, Hancock has a similar setup. Instead of a Velcro pouch, he has a glass jar with a piece of filter paper inside it. Crawling on top, under and all around it are close to a thousand bedbugs, the ancestors of which Hancock salvaged from an infestation in an Ohio nursing home in the 1990s. "If everybody was to feed right now, I'd have a thousand little needles stuck into my arm in this little patch," Hancock says. He's holding the jar upside down on his forearm, and the bedbugs are clambering to suck Hancock's blood through a screen on top. They haven't eaten since Thanksgiving.

Hancock hasn't tried to measure Denver's bedbug infestation, a monumental undertaking. He doesn't fully trust the rankings by Terminix and Orkin, but he does say that he considers the problem here "significant." His proof? In his eighteen years as a professor in Kentucky, he only ever heard of two groups of students experiencing problems with bedbugs: a student studying abroad in London and some collegiate swimmers who picked them up from a hotel in Florida during spring break. College students are at higher risk, he explains, because they're transient and tend to live in multi-unit apartment buildings decorated with hand-me-down furniture.

In his two and a half years at Metro, however, Hancock has heard dozens of stories from both students and colleagues alike. "I've had at least eight students who have personally brought me bedbugs," Hancock says.

While his evidence may be anecdotal, it's hard not to trust his expertise. This is a man who ventured to London, a city with a rich bedbug history, in search of an infested hotel room in which to spend the night, and then kept the cameras rolling as bedbugs crept across the white sheets and lined up to feed on the underside of his arm like a row of nursing puppies. Along the way, he filmed up-close footage of bedbugs mating -- "Oh, my! Look at that! Right there! He's got her!" -- and of bedbugs pooping. "Sometimes they poo on each other! Look at that guy! He has a beautiful black beret of poo!"

"It's almost like Indiana Jones meets Jeff Corwin," says Metro biology professor Sheryl Zajdowicz of Hancock's bedbug documentary. In the hour-long film, and in his previous self-produced documentary about mosquitoes, "Swamp Angels," he refers to himself as Mosquito Man. (He even has a catchy theme song, composed by his jazz-singer wife.) Zajdowicz, who specializes in molecular biology, and Hancock are teaming up to conduct a years-long experiment that will hopefully provide the Mile High City with some insight into its bedbug scourge. Using DNA sequencing, the scientists hope to determine where Denver's bedbugs are coming from.

"Bedbugs move with people," Hancock explains.

"We want to compare their genetics to see, is there a trend? Are we receiving them from one particular location?" Zajdowicz says.

With help from students, Zajdowicz will compare the DNA of Denver bedbugs to the DNA of bedbugs from different locations around the country. "He likes to grow them and feed them," Zajdowicz says of Hancock, whom she calls "Bedbug Bob." "I like to smush them up and isolate their DNA."

So far, the pair have collected bedbugs from ten sites around Denver. Zajdowicz hopes that in the end, they'll analyze hundreds. The results could help determine which treatment techniques are most effective here. Recent studies have shown that bedbugs are quickly evolving to withstand pesticides. New York bedbugs, for instance, are reportedly more than 250 times more resistant to certain chemicals than bedbugs in Florida, according to a study done at the University of Massachusetts.

"If we can identify where they're coming from, we can understand how to treat them," Zajdowicz says. "Is it necessary to do heat treatment, which is expensive? If you have resistant ones, the pesticides may not be working."

But for now, Hancock isn't thinking about killing bedbugs. He's thinking about keeping them alive. After twenty minutes of holding his screen-topped jar against his forearm, he pulls it away to reveal a dark red circle imprinted on his skin where the rim used to be. Inside it are hundreds of tiny red prick marks, evidence of the bedbugs' first square meal in more than two months. The bedbugs, bloated with blood, are scurrying around the jar like a colony of ants on a mission. Despite the bright fluorescent light that illuminates Hancock's small office, they're active, awake and looking to party.

"They're amazing insects," Hancock coos. "They cause a lot of problems for a lot of people -- and I don't want them in my bed, necessarily -- but I think they're awesome."

Unfortunately for the bedbug, he may be the only one.