They look like regular jars. For baby food, maybe. Or a charming collection of shells. But these jars are filled with tiny bloodsucking monsters. They’re bedbugs, housed (and fed) as part of research to create a new kind of trap based on pheromones. Regine Gries and her husband, Gerhard, both biologists at Simon Fraser University just outside Vancouver, British Columbia, have perfected a chemical lure capable of enticing bedbugs away from our mattresses—and our flesh—and into traps. But science takes sacrifice: Every Saturday, Gries rolls up her sleeves, slips off her watch, and lets a thousand hungry bedbugs feast on her arms.

The lab’s Plexiglas-walled bedbug colony currently has around 5,000 residents, which live in groups of about 200 inside glass jars covered with strips of fine mesh rubber-banded across the top. The security measures are important: “I don’t want them at home, and I don’t wish them on my worst enemy,” Gries says. If even one pregnant female got out, the lab could be infested within weeks.

Gries feeds as many as five jars’ worth at once, by holding the containers upside down against the length of her forearm and letting the bugs’ mouths (or, more specifically, their stylet fascicles) reach through the mesh and into her skin. Since the bedbugs get only one chance to eat per month, they’re hungry enough to overcome their natural fear of light; it takes just 10 minutes for all 1,000 of them to fill up. Gries likens the feeling of each bite to that of a mosquito, and she’d know, having previously served as an all-you-can-eat buffet for the lab’s mosquito colony on another project. Since the bedbug research began in 2006, Gries has been bitten some 200,000 times.

She’s an ideal host for her tiny subjects: Some people suffer allergic reactions to bedbug bites—a population that includes her husband. When he tried to feed just a few dozen of the colony’s residents, his arm swelled to twice its normal size. “We went to one of these walk-in clinics, and the doctor didn’t have a clue,” Gries says. Her symptoms, on the other hand, are comparatively minor: itchiness and swelling for about two hours. (She also changes the jars before each feeding for hygiene.) Letting the colony feed on fresh human blood is also less complicated and less risky than other approaches. At first one of Gerhard’s grad students tried feeding the bedbugs chicken blood from a nearby slaughterhouse, but it turned out the chickens had been medicated, and their tainted blood nearly wiped out the entire colony. Next, Gries got permission for the bedbugs to feed from a group of research guinea pigs kept on campus. That didn’t work either: The rodents had to be sedated and shaved before every single feeding, as the bedbugs couldn’t eat properly through their fur. Eventually, Gries took pity on the guinea pigs and decided to become one herself.

Now that their chemical lure is finished, a Canadian company is using this research to build a commercial trap that it hopes to bring to market this year. Which means it may soon be possible to stop bedbugs in their tracks, thanks to Gries’ blood, sweat, and tears. Well, mostly blood.