Keep them informed of at least some of your activities. My roommate and I have this major problem. I am early to bed, early to rise, and she does her best studying late at night, with her stereo on loud. We are really getting on each other's nerves. Some problems have easy solutions.
Headphones are a good cure for a stereo.
Other problems take a lot of work, if they can be solved at all. Maybe you can figure out some compromises. If that fails, ask the tutors on your floor for help. Look at your roommate situation as a challenging and worthwhile lab experiment on friction. Talk with helpful advisors.