Interns are a wonderful idea—in theory. You get to lessen a little bit of the old workload and the intern gets to ease that crushing transition into the real world. Yes, it would be a wonderful situation if that was actually ever how things played out.
By design, interns come to the office knowing nothing of the business that you do. Surprisingly, two to three years of sitting in a lecture hall studying the theory of your field hasn't yielded the Excel knowledge needed to get them through the day to day. As a result, anyone managing interns now has two jobs: doing everything they normally do, and finding something for the interns to do. This invariably creates a third job for the "internship coordinator" to enjoy that usually requires them to stay after hours: fixing problems created by interns.
Just hope that the interns are over 21 so that you can all go to the bar and release the tension created by their very presence after a month or so. Just don't hook-up with them, all of you would-be power abusers out there. Due to somehow having more connections than you in a field that you already work in, they will be your boss within five years, and will be mad that you never called.