How to Kill Stink Bugs in a Window Air Conditioner

Inspect your entire home for openings that may serve as entryways to stink bugs. Remove the window air conditioner from the window. Close the window and seal up any cracks and crevices surrounding it. Install screens on your windows and doors so bugs can't enter when you leave them open.

Pick up any stray stink bugs with a paper tissue and quickly flush them down the toilet -- otherwise they may crawl out. Avoid crushing the bugs when picking them up; they emit a foul odor.

Vacuum around the window and over the outer surface of the air conditioner to get rid of bugs inside and outside the unit. Due to the odor created when these insects are killed, it's a good idea to use an old vacuum, if possible. Either way, seal the vacuum cleaner bag and discard it in the trash outdoors. As an alternative, sweep up any visible bugs around the air conditioner and discard them outdoors.

Make your own stink bug repellent. Mix an equal amount of dishwashing liquid and water. Wet a washcloth with the mixture and wipe it over the window air conditioner surface. Stink bugs dislike water and soap, so the mixture may cause them to relocate. Spray the mixture on stink bugs sitting on the outside of your window screen to get them to leave.

Fill a jar with your homemade soap and water bug repellent. Wipe visible stink bugs from the air conditioner into the soapy water to instantly kill them. When the soapy water penetrates their bodies, they die without emitting a foul odor. Seal the jar once the stink bugs are trapped inside and discard it in the trash outdoors or flush the dead bugs down the toilet.

Use a stink bug light trap to kill the intruders. Position the air conditioner on the floor in a dark room. Set a commercial stink bug light trap in a corner of the room. Make this the only light source in the room. Stink bugs are attracted to light, because they associate it with heat. The remaining stink bugs abandon the air conditioner to go toward the light. Once trapped, they die of dehydration.

Treat the outer perimeter of your home with residual insecticide on a quarterly basis. Spray before the beginning of September, which is when the bugs are prevalent.

Use your window air conditioner from the middle of June to the end of August. Remove it at the beginning of September when stink bugs swarm.