This is a pillbug, sometimes called a roly poly. They are typically found outdoors and can ocasionally be found inside in areas that are damp (such as a basement). Additionally, pillbugs sometimes try to spend the winter in a warmer, indoor place and can be awakened from their winter inactivity by warmer outdoor temperatures. If there are only a few of these pillbugs, it's not likely a cause for concern. If you're finding 50+, that could be a sign of high moisture or dampness along a wall in a room.