Humans share their homes with hundreds of species of flies, spiders, beetles, lice and other arthropods, a new study reports.
Researchers visited 50 houses within 30 miles of Raleigh, N.C., and collected all of the arthropods they could find. They found 579 different morphospecies — meaning they were all physically different — from 304 different families.
The study, which appears in the journal PeerJ, found there were more than 100 species per house.
One arthropod found in all homes was the gall midge, a fly just four-one hundredths of an inch long. Although gall midges live only outdoors, they are probably blown often into homes, said Michelle Trautwein, an entomologist at the California Academy of Sciences and one of the study’s authors.
She and her colleagues also found many booklice, harmless cousins of head lice. “Basically, we are all are living with lice,” Dr. Trautwein said.
Although many different arthropods were found, most were benign.
“The vast majority of the arthropods we live with are not pest species,” Dr. Trautwein said. “They are not going to suck your blood, eat your food or destroy your house.”
To do their study, the researchers crawled around homes wearing kneepads and head lamps, and used forceps as well as an aspirator to suck up samples that they later studied under microscopes.
The scientists are now expanding their study to include homes on all seven continents.
“We’re aiming to find out more about arthropods in different kinds of houses and in different climates,” Dr. Trautwein said.
