They see those little spots, but they have no idea that it's spider poop.” 
 
 Now that you are suspicious about every speck you might see in your house, here’s what the researchers didn’t find: not a single brown recluse spider or bed bug. Arthropods—a huge group that includes insects, spiders, and their relatives—have been living and evolving alongside people for millennia. Typical household pests were found in a minority of the homes, such as German cockroaches ( Blattella germanica : 6% of houses), subterranean termites (Rhinotermitidae: 28% of houses), and fleas (Pulicidae: 10% of houses); bed bugs ( Cimex lectularius Linnaeus) were not found during the study. Only four families were identified from 100% of houses sampled: cobweb spiders (Theridiidae), carpet beetles (Dermestidae), gall midge flies (Cecidomyiidae) and ants (Formicidae). PeerJ 2: e523; DOI 10.7717/peerj.523 Each house was home to anywhere between 32 and 211 arthropod species, according to the study, published January 19 in the journal Peer J. Overall, there are more types of flies associated with human homes than any other group of animals. PeerJ 4:e1582; DOI 10.7717/peerj.1582 
 
 Martin et al. The carpet beetles and book lice do much of the clearing up, scavenging dead insects, moulds and algae, as well as polishing off food crumbs and detritus from our own bodies, including nail clippings, hair and dead skin. The rich arthropod diversity we identified from houses reflects a gradient of association with human habitations, from synanthropic arthropods that appear strongly adapted to human houses (cobweb spiders, carpet beetles, book lice), to others that seek shelter and resources only on occasion (ants, ground beetles, hunting spiders, smoky brown cockroaches), to many groups that simply become trapped in houses to their own detriment (leafhoppers, gall midges, click beetles). Arthropods within our homes are both diverse and prevalent, and are a mix of closely synanthropic species and a great diversity of species that wander indoors by accident.
– You thought Asian camel crickets were bad. A new report in journal Peer J finds hundreds of bugs likely lurk in your home, including spiders, beetles, ants, and book lice. Scientists got down on their hands and knees and combed 50 houses in the suburbs of Raleigh, NC, picking up any bugs they found, to determine the diversity of arthropods indoors. They "found far more diversity than most people would expect," study leader Matt Bertone tells National Geographic. More specifically, they gathered 10,000 bugs from 579 species. If that doesn't freak you out, this probably will: Each home housed 100 species on average, per New Scientist, though one revealed 211 species. And less than 1% of rooms were bug-free. "That old wives' tale that you're never more than 10 feet away from a spider? If you're in your home, that might be true," Bertone says. Every home contained ants, carpet beetles, cobweb spiders, and gall midges, which "rely on things we produce or have in our homes," says Bertone. About 98% held book lice, which eat mold and mildew, reports Wired. There were even some bugs scientists suspect might be new species. Since scientists searched carpets, floorboards, and shelves, but not behind walls, under heavy furniture, or in cabinets, they say more bugs are probably hiding nearby. On the plus side, most were harmless. "The residents were really surprised and often horrified that we found so much," says Bertone. But except for the occasional cockroaches, termites, and fleas, the bugs are "not dangerous and you won't see them unless you really look for them." Just think of them as "quiet roommates," adds a co-author. (Your home's dust contains 9,000 species of microbes.)