Staff Attendance and Working Hours

A graduate student works increasingly late night hours after other lab staff have gone home, and is less often present during the day.  His advisor asks the student to spend more time in the lab during the work day, when others are present, to enhance interaction with other researchers.  The student refuses, insisting that equipment he needs is rarely available during regular working hours and he is more productive at night when fewer people are around.  How can this conflict best be resolved?

K5R says:  This situation requires compromise by both parties.  The laboratory director has to have flexibility in allowing students and staff to work later if that is when they will be most productive, but the director is under no obligation to cave into the demands of students and staff who do not want to be present during the day to be properly supervised.  It would not be difficult to set up a schedule where the student spent half time present during the day (afternoons or perhaps alternating one day and one evening).