Animals

Here’s Where Bugs Are Likely to Live in Your Home

A study of home interiors found that the environment rather than residents’ lifestyles seems to determine where bugs are likely to thrive.

Katherine Frey/The Washington Post/Getty Images

New research finds that the number and variety of bugs in our living space depends on several hard-to-control factors, none of which have to do with how tidy we are. 

Researchers from the California Academy of Sciences, North Carolina State University, and Rutgers University surveyed 50 urban homes in Raleigh, North Carolina to study the arthropod communities living inside. The findings, published in the journal Scientific Reports, conclude that bugs prefer high-traffic, carpeted areas of first floor homes that have many windows and doors.

The survey is part of a seven-continent study of household insects and the effects they have on our health. The study will also include surveys of homes in Sweden, the Peruvian Amazon, Japan, Tanzania, Australia, Antarctica, and one other US city — San Francisco.

While indoor pests like termites and bed bugs have been studied extensively, little research has been conducted on the bugs that live with us but tend to mine their own business.

“I find it extraordinary that the indoor environment is in many ways less understood than more remote, natural areas because it has been overlooked for so long,” Misha Leong, lead author and postdoctoral researcher at the California Academy of Sciences, told Seeker. “[Pest] groups represent only a tiny fraction of overall indoor arthropod diversity.”

Images of most commonly collected famlies in basements. Photos by MAB. Basements had a unique set of arthropod families. (A) camel crickets (Rhaphidophoridae), (B) pill bugs (Armadillidae), (C) Millipedes (Paradoxosomatidae), (D) Moss mites (Oribatida).

The type of bugs found inside a home largely depends on the outdoor environment. But Leong’s team found that rooms on the first floor with a lot of doors and windows had more arthropods inside, as it provided easy access. In general, people in a ground or garden unit will have more bugs inside than those who live in a high-rise.

But if you live on the 15th floor, you might not be as lucky as you think. It turns out that having bugs inside may offer some surprising benefits.

“There are obviously some arthropod groups that we would rather not have in our homes that can cause structural or economic damage,” Leong said. “But there are also tiny predators and scavengers that provide tidying and pest control services free of charge and having greater diversity may suppress pest outbreaks from occurring.”

Other research suggests that certain modern ailments are caused by lack of exposure to microbial diversity. But indoor bugs may help spread those microbes around a house, effectively doing us a favor. “Greater biodiversity in a home may be an overall indicator that the home is a healthy environment,” Leong said. 

Having many house plants could help attract more of those good-for-you type of bugs. A previous study from the academy found that homes in higher income neighborhoods have a greater number of species types living inside. One reason for this may be that these homes tend to have a variety of indoor plants, attracting more plant-loving bugs and allowing them to thrive. 

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In the study of Raleigh homes, the team observed that common areas like living rooms tended to host more critters than kitchens, bathrooms, or bedrooms. But the same species of bug could be found in every room of the house.

“We did find some similarities in the composition of arthropods collected in different room types, but it was almost more surprising how certain groups could be found across all room types,” Leong said. This can likely be attributed to the ‘island effect.’ Once a species gets inside, they colonize their new home and disperse throughout the house. 

It’s little surprise that basements are the critter capital of the home, attracting “cave dwellers” like spiders, centipedes, camel crickets, and ground beetles. One spider species, the long-legged cellar spider, was more numerous in cluttered areas, but overall, tidiness and other human behavior did not greatly affect the number or variety of bugs in any house. 

Dogs, cats, or other household pets didn’t seem to have an influence either, which added support to the theory that the critters that end up in your house are more dependent on the environment than on residents’ lifestyles. 

As Leong’s team takes their research to other countries, they’re curious to see if their findings will hold true elsewhere.

“As humans, we tend to prefer certain comforts in our living spaces, but the diversity of living spaces and outdoor environmental contexts can vary immensely,” Leong said. “By studying homes around the world, we can better understand human-arthropod relationships and the environment of the indoor biome.”

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