A cheap homemade stink bug trap can outperform commercial options, and the most effective version costs almost nothing to build. Researchers at Virginia Tech found that a foil roasting pan filled with soapy water, placed under a light in a dark room, was the best method for trapping stink bugs indoors. You can build one in under five minutes or opt for a reusable bottle trap that works on the same principle.
The Soapy Water Pan Trap
This is the simplest and most research-backed design. You need a disposable aluminum roasting pan, water, dish soap, and a desk lamp or clip light. Fill the pan with a few inches of water, add a generous squirt of dish soap, and set it on the floor of a dark room with the light positioned directly above it. The soap breaks the surface tension of the water, so when stink bugs fly toward the light and land in the pan, they sink and drown instead of walking across the surface.
The key to making this work is darkness. Stink bugs are strongly attracted to light, especially ultraviolet wavelengths. When the pan trap is the only light source in the room, it becomes a magnet. A standard LED desk lamp works, but if you have a UV or blacklight bulb, that’s even better. Set the trap up at night in rooms where you’ve noticed the most activity: attics, spare bedrooms, or rooms with south- or west-facing windows where the bugs tend to congregate.
The 2-Liter Bottle Trap
A bottle trap is more contained, portable, and reusable. It works like a minnow trap: bugs climb in through a funnel and can’t figure out how to get back out. Here’s how to build one.
Take a 2-liter soda bottle and cut it roughly three-quarters of the way up from the bottom. Flip the top piece upside down so the neck points downward into the bottom half, creating a funnel. Tape the two pieces together securely. Place a small push-button LED light in the bottom of the bottle as your light source. Then wrap the outside of the bottle with dark construction paper or black tape so that light only escapes from the funnel opening at the top. This forces the bugs to enter through the narrow opening to reach the light.
For extra effectiveness, add about a cup and a half of water mixed with a tablespoon of dish soap to the bottom. Bugs that fall through the funnel land in the soapy water and can’t escape. If you skip the water, the funnel alone will still trap them, but some may eventually crawl back out. One more detail that helps: stick a few strips of masking tape vertically along the outside of the bottle. The smooth plastic is hard for stink bugs to grip, and the tape gives them traction to climb up to the funnel entrance.
Where and When to Set Traps
Stink bugs enter homes in September and October, driven indoors by shorter days and dropping temperatures. They tend to arrive on warm, sunny afternoons, crawling through gaps around windows, doors, soffits, and utility penetrations. Once inside, they tuck themselves into wall voids, attics, and unused rooms to ride out the winter. You’ll see them again on warm winter days when they become active and wander toward windows and lights.
Place traps in the rooms where you spot them most. Attics, upstairs bedrooms, and rooms near the roofline are common hot spots because bugs often enter from above. Set traps on the floor away from competing light sources. If a streetlight or nightlight is pulling their attention, the trap won’t work as well. The darker the room, the more effective the trap becomes.
You can run these traps any time stink bugs are active indoors, but the biggest catches tend to happen in early fall when they’re first moving in and again in late winter or early spring when warming temperatures wake them up.
Why Pheromone Lures Don’t Work Indoors
You might see commercial pheromone traps marketed for stink bugs. These use a synthetic version of the aggregation scent that stink bugs release to attract others. While pheromone traps are useful for monitoring stink bug populations outdoors in agricultural settings, they don’t work during the overwintering period when bugs are inside your home. The bugs simply aren’t responding to aggregation signals while they’re in their dormant winter state. Light-based traps are the right tool for indoor use.
Emptying Traps Without the Smell
Stink bugs release their defensive odor when they feel threatened or get crushed. The soapy water in both trap designs actually works in your favor here. Bugs that drown in soapy water don’t release nearly as much odor as ones you’d squish or vacuum up. When it’s time to empty the pan trap, just carry the whole pan outside and dump it. For the bottle trap, unscrew or untape the funnel section, pour out the water, and refill. Replacing the soapy water every few days keeps the trap effective and prevents it from getting foul.
If you’re using the dry bottle trap without water, dump the trapped bugs into a sealed plastic bag before tossing them. Avoid crushing them inside the trap, or the smell could linger and potentially discourage other bugs from entering.
Reducing Entry in the First Place
Traps help manage the bugs that are already inside, but sealing entry points is the other half of the equation. Stink bugs squeeze through surprisingly small gaps. Caulk around window frames, door frames, and where pipes or wires enter the house. Check weatherstripping on exterior doors. Repair or replace torn window screens. Pay special attention to the upper levels of your home, since bugs often land on sunny exterior walls and work their way in through gaps near the roofline, attic vents, or chimney flashing.
Doing this work in late summer, before the September migration begins, makes the biggest difference. Once they’re already in the walls, no amount of sealing will keep them from emerging inside on warm days throughout the winter.