Your fresh and well-performing furnace filter picks up a lot. Pollen, pet fur and dander, mold spores, and, at the highest MERV ratings, even strains of bacteria are no match for your filter. For people with allergies, one of the most important jobs a filter has is mitigating exposure to a microscopic menace named Dermatophagoides farinae, which we know better as the house dust mite.
What is this tiny bug, and why is it such a problem? What does it take to make it go away? Am I breaking out in hives all over my body because I’m under attack by a hungry herd of dust mites? We’ll do our best to answer your questions about coexisting—or refusing to further coexist—with the dust mite. Without further ado, here’s everything you need to know about dust mites but shouldn’t be afraid to ask.
What Is a Dust Mite?
Dust mites are arachnids, eight-legged arthropods with exoskeletons. The arachnid class is a large one that also includes such disparate creatures as scorpions, ticks, and the best-known arachnids, spiders. The arachnids are a wide-ranging group of animals, and beyond their octets of articulated limbs, they don’t have a great deal in common. Unlike scorpions, dust mites don’t have powerful stingers, and unlike ticks, you won’t catch them latching onto your legs while you’re on a hike. They don’t weave webs as spiders do, either. So, what exactly do dust mites do all day, anyway?
A Mite-y Appetite
Basically, dust mites eat—a lot. Let’s do a study in contrast with another renowned glutton, the bedbug. Every child (and the occasional adult) goes to bed with the gentle admonition not to let the bedbugs bite. But bite they often do, and with bedbug infestations puzzlingly on the rise in the last decade, an increasing number of hotel guests and residents alike have woken up with bedbug bites. Bedbugs and dust mites love your bed as much as you do, but they have very different interests.
While bedbugs are true parasites who feed on human blood, dust mites are detritivores—they prefer organic material that’s already dead and discarded. Have you ever had a sunbeam hit your room at such an angle that all the ambient dust in your room is visible? What you see is a mite’s smorgasbord of skin flakes and other tasty particles. Think of them as a little clean-up crew, gobbling up all those flakes of dead skin to keep them out of your way. There’s only one problem here—all that digested food has to go somewhere, right?
Cleaning Messes, Making Bigger Messes
Dust mites may be small animals, but they’re animals nonetheless, and they have not been expertly potty-trained. It’s the feces of dust mites that cause our allergic reactions. As dust mites dutifully digest detritus, they not only defecate but also excrete digestive enzymes as a byproduct of their digestive process. Two variants of the peptidase-1 enzyme, code-named Der p 1 and Der f 1, trigger immunoglobulin E production and subsequent allergic reactions in humans. Thus, it is not the dust mites themselves (who would be content to eat our detritus and leave us alone) that pose such a problem to us, but rather their tiny fecal particles. How tiny are we talking?
Invisible To the Naked Eye
If you think you see dust mites buzzing around the tufts of dust under your bed, you’re definitely seeing something, but this time, that something isn’t dust mites. Dust mites themselves are tiny, usually measuring only about 300 to 400 microns long. On the high end, that’s two-fifths of a millimeter or about 1.5 percent of an inch. That’s small. Consider, then, that their excretions will be even smaller.
Moreover, their bodies are translucent, making them even harder to spot, even if you’re getting as up close and personal with some dust as you can get. You’ll need a powerful microscope to see a house dust mite in all its eight-legged glory, and chances are you won’t like what you’ll see. After getting a closer look at what resembles a stubby-legged but extremely bloated tick, you’ll be glad you don’t have to make eye contact with them.
The Particulars of House Dust Hospitality
As you might guess from a being that is nearly transparent and only a tiny fraction of an inch long, dust mites are not the most rugged creatures on the planet. Despite a worldwide distribution and innumerable population, dust mites are highly particular about where they choose to live. Dust mites require darkness, moderate to high humidity, and a narrow range of temperatures. Unfortunately, that narrow range is what we think of as “room temperature,” running from about 68 to 76 degrees Fahrenheit. Maintaining a relative humidity level under 40 percent will desiccate the mites. It will also desiccate your house. Just as high humidity can cause dangerous off-gassing of furniture and building materials, low humidity can cause cracks in paint, woodwork, and doors, not to mention the damage it can do to your furniture. Control your humidity with caution.
Another Mite Bites the Dust
Dust mites are nature’s goths—they do not like sunlight. Whereas stepping into the light merely vexes your average fan of the Cure, it’s enough to kill dust mites. A combination of ultraviolet rays and dehydration from elevated heat will kill dust mites, halting the production of the harmful bacteria and enzymes that send your immune system into overdrive. Unfortunately, UV exposure won’t do anything about the byproducts themselves, which can still linger after the mites are dead.
What Else Can We Do To Foil These Mites?
Among everything you need to know about dust mites, what you surely want to know most is how you can limit your exposure to these benign bugs and their irritating droppings. When taking things outside isn’t an option, regularly vacuuming should be your first step, along with laundering your bedsheets often to flush out dust mites and denature the enzymes they leave behind. Finally, use high-performance pleated furnace filters to capture as many tiny airborne particles as possible. With MERV ratings that range from 8 to 13, these filters can trap dust mites, their food source, and the allergens they leave behind, leaving you and your family breathing better.
