Mondays and Wednesdays, I work from 10-5 as part of an unpaid internship. I've been finding myself really short on actual, substantive work. They have a very unstructured way of sending tasks -- I have one "long term" busy work type assignment, and then I can be assigned various projects as my (4-5) bosses see fit. In the past few days, this has been happening quite rarely.
My bosses are very busy and I feel awkward constantly asking if there's "anything I can do", but I don't think it's particularly constructive for me to sit around all day either.