The stink bugs invading homes across North America are originally from East Asia. The brown marmorated stink bug, the species most people are dealing with, is native to China, Japan, and Taiwan. It arrived in the United States sometime in the mid-1990s, likely as a stowaway in shipping containers, and was first formally identified in Pennsylvania in 2001. Since then, it has spread to at least 43 states and four Canadian provinces.
Native Origins and How They Got Here
In their home range across East Asia, brown marmorated stink bugs are kept in check by natural predators and parasites that evolved alongside them. Removed from those controls, they thrived in North America. The initial population in eastern Pennsylvania exploded over about a decade, and by the late 2000s the bugs were causing serious agricultural damage across the Mid-Atlantic states. They spread westward through a combination of natural flight and hitchhiking in vehicles, luggage, and shipped goods.
North America does have its own native stink bug species. The green stink bug and the brown stink bug are both indigenous and widespread from Quebec to California, though they cause more crop damage in the southern U.S. There are also predatory native species, like the spined soldier bug, which actually eats other insects. But the brown marmorated stink bug is the one that shows up in homes by the hundreds, and that behavior is a major reason people notice it more than any native species.
Why They Show Up in Your House Every Fall
Stink bugs don’t breed indoors. They enter your home in autumn looking for a warm, sheltered place to spend the winter, a survival strategy called overwintering. As temperatures drop, they treat your house the way they’d treat a heated rock outcropping in the wild: a place to go dormant until spring. A sun-facing exterior wall is especially attractive to them, which is why you’ll often see them clustering on the south and west sides of buildings on warm fall afternoons before finding their way inside.
They squeeze through remarkably small gaps. Common entry points include cracks around windows and doors, torn screens, gaps where utility pipes or wires enter the foundation, spaces under sliding glass doors, and openings around attic or crawl space vents. Once inside wall voids or attic spaces, they settle into a dormant state. You may not see them again until a warm winter day or early spring tricks them into becoming active, at which point they wander into living spaces looking for a way back outside.
Their Life Cycle Outside Your Home
Adults emerge from overwintering sites in late April to mid-May, once temperatures warm consistently and daylight reaches 12 to 13 hours. They mate shortly after, and females deposit eggs from May through August. The eggs are light yellow to yellow-red, laid in clusters of 20 to 30 on the undersides of leaves. They hatch in 6 to 26 days depending on temperature.
Brown marmorated stink bugs feed on an enormous range of plants. Apples, peaches, apricots, figs, mulberries, citrus, persimmons, beans, corn, tomatoes, soybeans, and many ornamental plants are all fair game. This broad appetite is a big part of why they’ve spread so successfully. Trapping data from eastern Washington shows two adult activity peaks each year: one in mid to late May and another in July and August, corresponding to overwintered adults and the new generation.
Keeping Them Out of Your Home
Exclusion is the most effective strategy, and the work needs to happen before fall. Seal cracks around windows, doors, and fascia boards with silicone or acrylic latex caulk (latex types clean up with water and can be painted over). Install door sweeps on all exterior doors. Fit garage doors with rubber bottom seals, since vinyl seals become rigid and ineffective in cold weather. Line the bottom track of sliding glass doors with half-inch to three-quarter-inch foam weatherstripping.
Seal utility openings where pipes, wires, outdoor faucets, gas meters, dryer vents, and cable lines penetrate the foundation or siding. Expandable foam, steel wool, copper mesh, caulk, or cement all work for plugging these gaps. Repair any tears in window and door screens. For attic, roof, and crawl space vents, install quarter-inch wire mesh hardware cloth to block entry.
Removing Stink Bugs Already Inside
The cardinal rule: don’t crush them. The defensive odor they release is persistent and unpleasant. There are no residential insecticides labeled for indoor use against brown marmorated stink bugs, so chemical sprays aren’t an option anyway.
The simplest approach is a vacuum cleaner with a bag you can seal and discard immediately, since the smell can linger inside a canister vacuum. For a more targeted method, Virginia Tech researchers found that a foil roasting pan filled with water and dish soap, placed under a desk lamp in a dark room, outperformed commercial traps. The light attracts the bugs, and the soapy water traps them. It’s cheap, pesticide-free, and effective for clearing a room overnight.
Natural Predators Catching Up
One reason brown marmorated stink bugs became such a problem is that nothing in North America evolved to target them specifically. That’s changing. A tiny parasitic wasp called the samurai wasp, native to the same East Asian range as the stink bug, has established itself across much of the northeastern and west coast United States. It’s roughly 1 to 2 millimeters long, and it kills stink bugs by laying its own eggs inside stink bug eggs. The developing wasp larva consumes the stink bug embryo, and a new adult wasp emerges about 10 to 14 days later.
In their native range, samurai wasps destroy up to 80% of stink bug eggs, typically attacking every egg in a cluster. They aren’t commercially available for purchase, but they’re spreading on their own and are now found in both rural and urban areas. If you want to support their presence near your property, avoid broad-spectrum insecticide sprays, which are highly lethal to these wasps. Nearby wooded or weedy areas provide the nectar and overwintering habitat the wasps need to survive and reproduce.