Stink bugs are usually relatively large insects with an oval or shield-like shape. They can produce a nasty odor, which seems to be a defense mechanism of sorts against predators. Since their body shape is flat, these bugs can slip through cracks and torn screens easily, and they are often found trying to get into homes during the winter months. As it gets colder, they try to get indoors and enjoy the heat of a home. They also love light and sun, and they are found during the day, lounging on sunny walls, or during the night, near electric lights.
Stink bugs aren't hard to spot, and the best thing to do to get rid of them is to prevent them from coming in, by making sure all the cracks in your home are sealed, and that you use proper measures, such as bug screens.
While not particularly dangerous to humans, stink bugs can actually damage plants, fruit trees, and garden grass, since they actually feed on fruit, berries, and grass. Their smell can also be offensive, especially when they die by getting too close electric light sources, releasing a foul smell with their carcasses.