When Spring comes, the stink bugs come out of hibernation and slowly start to move around your house as they get ready to leave and mate. You will probably notice a significant increase in stink bugs as soon as the days start to get warmer. This is a perfect time to use an indoor trap. The best spot to place one is in the attic, and if you can put one near a light source you will be much more effective.
As Summer starts the stink bugs that were in your house will mostly be outdoors. But they haven't gone far. They tend to stay very close and feed on the trees and shrubs in your yard. This provides an excellent opportunity to trap them outdoors and spray a perimeter barrier of insecticide around the base of your house. The goal for the Summer months is to trap them outside. Then, when Fall arrives, the bugs won't be able to enter your home to continue the cycle.
At the beginning of Fall, when the days get shorter and the temperature decreases, stink bugs seek shelter. They need somewhere safe and quite to hibernate. This is typically the time you will start to see stink bugs entering your home from cracks and windows. Once a stink bug gets into a structure, it releases a pheromone that attracts many more. It's also why you might start to see them show up quickly and without warning.
During Winter hibernation, stink bugs will find a safe and quiet area of your home to rest. Their favorite hibernation spot is in your attic. They won't technically be asleep, but it can look that way. They won't move, and the female stink bugs will no longer lay eggs. For the most part, they won't be very visible during the winter months, and they are not interested in leaving your house until it is time for them to mate in the Spring.
In general, homeowners tend to report stink bugs the most during the Fall and Spring months. This is the time when they are the most visible. However, they never go away. If you know what you are doing you can kill or trap them any time of year. Once you know where they are, you can easily break the cycle and get rid of your stink bugs for good.