The answer to 'why is my stink bug invasion' is that stink bugs are a common household pest that can quickly infest homes, especially in the fall when they seek warm shelter. Stink bugs release a foul-smelling odor when disturbed, which is how they get their name. They feed on a variety of plants and crops, and can become a nuisance when they congregate in large numbers inside homes.
Stink bug infestations are often caused by cracks and gaps in the home's exterior that allow them to enter. They may also be attracted to lights at night and find their way indoors. Signs of a stink bug problem include seeing the bugs themselves, noticing their distinctive odor, and finding small brown spots on walls or furniture where they've been squashed.