This is an article from the spring 2015 issue of LSA Magazine. Read more stories from the magazine.

Meet the dust mite—a tiny bug that moves across the globe by clinging to your coat sleeve or carry-on bag. One LSA researcher is shining a light on the minuscule mites to better understand how they travel and more accurately predict reactions in people who are allergic to them.

Don't be alarmed, but it’s possible that you have a few—or a few hundred—roommates that you didn’t know about.

Meet the house dust mite, a minuscule arthropod that eats dead skin and lives in places where human skin particles accumulate—namely, your bed.

“Dust mites can live in your bed, and especially your pillows,” says Pavel Klimov, an assistant researcher in LSA’s Department of Ecology and Evolutionary Biology, who studies house dust mites. “But you might not see them. They are so small that even against a black background, they are only just visible as whitish specks to most people.”

For a long time, dust mites lived in birds’ nests, and they evolved the ability to digest the nutritive content in tough materials, such as bits of feather. To do that, dust mites developed a powerful enzyme that is often still active in their waste. Humans have to deal with that enzyme once the mites’ waste goes airborne.

“It gets into the air, and you breathe it into your lungs, and it begins to break down the very delicate cells that are in your lungs,” Klimov says. Contact with the enzyme can cause an allergic reaction, and some studies even suggest that exposure to mite waste can make people more likely to have other kinds of allergic reactions to things like food and pollen.

Have Enzymes, Will Travel

Klimov’s research into dust mite genetics is shedding light on how dust mites travel, and he’s hoping that his findings will help allergy sufferers better understand the true causes of their problems.

While working with a former student to sequence DNA strands from various dust mite populations, Klimov discovered that some dust mites in North America share a rare mutation with other dust mites from across the globe, in South Asia. That meant that the critters were somehow getting all the way from Islamabad, Pakistan, to Ishpeming, Michigan. The only explanation that made sense was air travel.

“Dust mites can grab onto your clothes or your skin, your food or luggage,” Klimov says, and move with you all the way from ticketing through security, onto the plane, and on to your final destination.

This research on dust mite variation has important implications for medical tests and allergy diagnoses. Right now, doctors apply a skin prick test using an inactive version of the dust mite enzyme to identify whether a person experiencing allergies is reacting to house dust mites or to something else in the environment.

“For mites, doctors use an inactive form of this digestive protein for the skin prick test, but variations in that enzyme can make certain tests in certain situations inaccurate,” Klimov says. “So there is an important link to be made between a deeper understanding of mites and direct medical applications.”

As for whether you have dust mites in your bedspread or not, the chances are pretty low overall, but get much higher if you’re near the water.

“Most people who are affected by dust mites live in coastal areas,” Klimov says. “Mites can live at subzero temperatures and they won’t die, but humidity is a key factor for them.”

If you identify mites in your house, you have options. You can use a dehumidifier to lower the moisture in the air, and you can replace your bedding materials or wash them in special washers that reach 140 degrees Fahrenheit, which kills the mites.

But most people aren’t harmed by contact with dust mites’ digestive enzymes, making the critters largely harmless, near-invisible roommates.

Sleep tight.