Despite the stubbornly high unemployment rate among millennials, millions in this cohort are working office jobs side-by-side with boomers who haven’t yet retired.

Given the age gap, the opportunity for conflict between generations is ripe, and it’s about more than just who forgot to clear leftovers from the office fridge. Millennials will make up 34 percent of the work force next year, but they’ll comprise 46 percent of workers by 2020, according to a report by the University of North Carolina.

Boomers and millennials have different views of work and life, which can clash in an office environment. Almost 25 percent of HR professionals reported some generational conflict in the workplace, according to a poll by the Society for Human Resource Management, in 2011, the most recent time the association examined the issue.

Click here to read about seven areas in which boomers and millennials just don’t see eye-to-eye when it comes to work.