All your unseen houseguests

In one of the most interesting scientific studies we’ve read in a long while, researchers conducted a zoological survey of sorts in an unlikely location: the average American household. Researchers wanted to survey the diversity of life inside the average, moderately cleaned household, from the floorboards up.


To do so, scientists crawled through homes using microscopic glasses, pincers, and an aspirator to suck up microscopic life. Most creatures that dwell inside our homes at a scale smaller than the naked eye can pick up fall into the category of arthropods. Arthropods are invertebrate creatures that have segmented bodies and long, jointed limbs. They’re largely harmless, but some varieties (like fleas or head lice) can be a real bother, while others (like dust mites) simply cause sneezing.

bed bug

Researchers expected to find a few common species that we’ve known about for a while, such as the ones just mentioned and book lice, which are one of the most common critters to live in all of our homes. Unlike their head-dwelling cousins, book lice are harmless, and eat dust and mildew that collects on paper products, especially in damp homes.


Instead, they were staggered to discover that the average home was hosting 100 different species, most commonly ants, booklice, beetles, and spiders. Most live where you wouldn’t see them, in cracks between floorboards and deep in carpet fibers, eating tiny particles of dead skin and hair, or collecting dust particles.


The homes surveyed for this study spanned a wide socioeconomic range, but they were all about 5000 square feet, and detached from other buildings to provide a good independent sample. Interestingly, the socioeconomic effect on microscopic diversity seems inversely proportional to most expectations, which is that poorer homes tend to be dirtier, and therefore would house a wider range of life. On the contrary, more affluent households saw higher measures of diversity.


The researchers who conducted the study said that while many Americans may be alarmed to learn just how many creepy crawlies are living under their noses, there’s nothing much to worry about. Unless you have an allergy to something like dust mites, or are seeing your books nibbled by lice, you’ll probably continue to coexist with your tiny neighbors for years. Still, it’s fascinating to know that our homes are much less sterile than we’d like to think!


It’s not all peaches and cream, though, because more Americans than ever are suffering allergic reactions to tiny particles and microscopic critters. The big takeaway for allergy sufferers from this study is that we’ve got  a lot more work to do to really address allergens in the home, from using vacuums with better, finer filters to doing a better job of cleaning into corners, cracks and carpets. Otherwise, chronic conditions may continue even in a relatively clean home.

man sneezing
For more on tiny problems that can escalate quickly, check out our post on tiny car tweaks! We’ve looked at a few key things you can address on your car to prevent big problems down the road, like cleaning your fuel injectors and checking your ball bearings!