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Growing plants can seem intimidating, but we believe anyone can create a thriving home conservatory of any size. We’re here to help nurture your skills and help make that happen, so please feel free to send any plant-related questions of your own to ask@popsci.com with “Plants” in the subject line.

Sydney Crawley doesn’t kill the spiders on her windowsill. Instead, the assistant professor of urban and structural entomology at North Carolina State University uses them as her personal exterminators.

And if anyone needs a platoon of eight-legged minions, it’s Crawley: She lives next door to a cattle farm and struggles with the inevitable houseflies that are drawn to the cows. “No matter what I do, I’m going to get a straggler in the house,” she says. But her windowsill spiders have come to the rescue, trapping three or four flies every few days. “The only issue is sometimes my dog will find them and boop them to death,” she says of her productive (if sometimes unlucky) roommates.

Her home, like yours, is not a sealed-off fortress. Living creatures that aren’t on the lease will inevitably find their way inside. On the smallest level, your living space has a microbiome, with up to 500 to 1,000 species or microbes living in your dust. A few rungs up the size scale, silverfish, spider mites, ants, fungus gnats, and cockroaches can be mild nuisances or a huge problem. They can kill your houseplants and raid your cupboard. Just as introducing wolves back into Yellowstone National Park led to increased soil aeration, better songbird habitat, and stabilized river banks, a few household apex predators like earwigs, spiders, and harvestmen could change your home for the better. Most North American spiders, including the cellar spiders on Crawley’s sill, are not dangerous to humans (or pets) anyway. So don’t smush those helpful neighbors if you can help it, and think about employing some of the following strategies for backup. 

Buy carnivorous plants 

A couple well-placed carnivorous plants can snag dozens of gnats or flies, as I can attest from personal experience. I placed a Mexican butterwort in my kitchen and it caught many annoying fruit flies that bred when I let oranges sit in my fruit bowl for a little too long. Also, it occasionally grew a charming purple flower. Daniela Ribbecke, office manager at California Carnivores, recommends both the Mexican butterwort and the Cape sundew if you have a sunny windowsill. 

Look for bug-resistant houseplants

I have a pet theory that fiddle leaf figs (along with crotons) are the worst, most fussy houseplants, no matter how many times Bobby Berk uses them on Queer Eye. Mine struggled with chronic spider mites. To my surprise, the nearby snake plant seemed to have no sign of these common pests. Some sources suggest that’s because of the thick, dust-resistant leaves. A little bit of pre-purchase research on whether a plant is susceptible to fungus gnats, spider mites, and other common pests could save you time and energy. My tip: don’t fall for the fiddle leaf fig hype! 

Get a ladybug or praying mantis tent 

You probably won’t be able to buy a spider at the local nursery. However, you can usually find refrigerated ladybugs, or even praying mantises. These insects will helpfully attack your smaller enemies, especially soft-bodied ones like aphids (praying mantises can, terrifyingly, also eat mice). Crawley notes that if you’re going to buy some of these to deal with a houseplant pest problem, it’s better to let the battle happen outside. “I’ve been in plant labs where even when you try to keep aphids and other insects that you’re trying to work with contained, you always have some escapees,” she said. This could be problematic indoors, especially because stressed-out ladybugs can secrete a yellowish substance that causes some people to have an allergic reaction. 

If a pest problem is out of control, it is probably too late to rely on spiders, carnivorous plants, or any other DIY solutions. But aside from that, if you can control your squeamishness and begin to think of your home as a well-controlled garden rather than a sealed box, you might be able to make friends with your fellow residents and tend to your personal ecosystem.

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