The occupants of your home you didn’t know about

This wasp was only about 1 millimeter long, or about 0.039 inches.

Even so, the sheer numbers of previously uncharted insect and spider species may effect our health, like microbes, the tiny single-cell organisms that live in and around us. Which makes you think that just because they didn’t identify numerous more unwelcome critters, doesn’t mean they weren’t around hiding in deeper recesses. Arthropods include insects, spiders, and centipedes, all of which are descended from a single common ancestor.

Researchers from North Carolina State University found almost 600 species of spiders, beetles, flies, and other insects across 50 free-standing homes-all of which were fully-occupied and well-maintained-within a 30 mile radius of Raleigh, North Carolina. In fact, hundreds of distinct kinds were discovered in a cross-sample of U.S homes conducted by researchers at North Carolina State University, the California Academy of Sciences, and the North Carolina Museum of Natural Sciences.

For their study, the researchers 50 houses in or near Raleigh, N.C. between May and October of 2012, searching for any and all arthropods in any state. Going room by room, they collected all of the arthropods they could find, both living and dead.

Scientists discovered that the dwellings they examined were inhabited by 579 various types of arthropods. “Conservative species estimates by home ranged from 32 to 211, with an average of 93.14”. “For instance I didn’t expect some groups to be in every home we sampled, and I would not have expected, for example, cobweb spiders to be found in 65 percent of rooms”. The method allows scientists to classify specimens based on obvious morphological differences between individuals – extensive taxonomic training not necessary.

“Many of the arthropods we found had clearly wandered in from outdoors, been brought in on cut flowers or were otherwise accidentally introduced”, said Bertone. While they may be gross to those of us who aren’t bug lovers, camel crickets are considered harmless – although they can jump pretty high and are super quick. In one home, the presence of several flesh flies led to the discovery of a rotting rodent carcass killed by a pet cat.

This is the first large-scale research of such kind and it will possibly open up a new avenue for studying arthropods living in homes.

To find the arthropods, a team of entomologists donned headlamps and knee pads, because they “learned early on that crawling around on the floor takes a toll on your knees”, Bertone said.

“My hope is that this doesn’t freak people out but people need to know their houses aren’t sterile environments”. “Now that we have a better idea of which species are most common in homes, we can focus on studying them”.

It seems that we know very little about our closest roommates. “But these insights give us the opportunity delve down into some exciting scientific questions. Many creatures may be drawn into a home by light or shelter, but they can’t survive there.

Some of the arthropods act like predators, while others come from the outside and do not last long, researchers said, stressing that most of the species are peaceful and far from being pests.