You can house them all together permanently. It's called 'harem breeding'. You will 'wear out' the female much faster this way. In some cases if she is malnourished she may decide to eat a litter to keep the nutrients she put into them if she feels her own health is in danger. I don't think it really happens that much though.

My first breeding I had a litter of 18 from a first time mom and that's been my record.