Our houses are comfortable enough for the bugs that creep through our basements, scuttle across our kitchen floors, and crawl across our carpets, according to a team of entomologists from North Carolina State University and the California Academy of Sciences. Lots of different bugs live in the parts of our homes that have access to the outdoors, no matter how tidy they are, the team reported Friday in the journal Scientific Reports.
The researchers picked up more than 10,000 bugs, both living and dead, from 50 houses in the Raleigh, North Carolina area. Roughly 47 families of harmless bugs showed up in most of the houses, including silverfish, book lice, fruit flies, and ladybugs. Pests like bedbugs, termites, and fleas were rarer, although, it’s important to keep in mind that we’re talking bug diversity here, not bug density. The study is more about the types of bugs, and less about their numbers.
Carpeted, ground-floor living rooms with lots of access to the outdoors were home to more types of bugs than other rooms. That could be due to a couple of reasons: because a typical living room tends to be bigger than, say, a shared bathroom, there are more spaces for bugs to live. Plus, more windows and doors to the outside could let in a more diverse community of creepy crawlies. The carpet is harder to explain: it could be because more bugs like to live there, or because more bugs tend to get stuck and die in its plush fibers.
It didn’t matter how clean the houses were, either. Residents filled out surveys about how many plants and pets lived with them, and researchers scored houses for clutter and filth. Pets mattered more than cleanliness, the researchers discovered — but not enough to make reliable conclusions. Homes with dogs had slightly more types of bugs. Homes with cats had fewer, possibly because cats eat the bugs.
The study is just a snapshot. The team only surveyed 50 houses within a single geographic area, so the patterns may change across different regions, even different seasons. (The team is scaling up their investigations to six continents for future studies.) The study also doesn’t say how much warning the researchers gave before visiting people's homes; residents might have tidied up knowing that a team of entomologists was about to pay them a visit. That could have skewed connections between cleanliness and cohabiting bugs.
Still, the study is a step toward getting to know the diverse community of creepy crawlies that share our homes. After all, we spend roughly 90 percent of our time indoors, and we only pay attention to the creatures that make nuisances of themselves. It’s high time we get acquainted with our more secretive roommates, too.