Interns should not feel like they have been added to the team via some duct tape. An article at Internships.com gives tips for integrating them more fully. For instance, you can ask the full-time team members to make the first move in getting to know the interns, since they might be shy or worried about intruding on people’s work time. You can also assign interns non-supervisor mentors, so that they can learn while feeling less pressure. And if the option exists, consider hiring more than one intern at a time. In situations where they would be entering into a long-established team, it can help for an intern to have another person with whom he or she can relate.
For more tips along these lines, you can view the full article here: http://www.internships.com/employer/resources/program/how-to-help-interns-fit-in-6-tips-for-making-interns-part-of-the-team