Senate expenses: what you need to know

The travel habits and housing arrangements of some Canadian senators have been under the microscope in recent months.

The ongoing controversy led to audits of four senators' expense claims.

More: Key moments in the Senate expenses controversy

Whether any criminal charges will come out of this won't be known for some time, as the RCMP investigates some cases. But the controversy has already caused some to rethink the upper chamber and how it operates.

Take a look below for key facts about the Senate and more about the expenses scandal.