I use to have around 130 mice at one time. They were fun to watch. I had 1 baby tank, 1 young mouse tank, 2 teen tanks, 1 male tank, 1 female tank, 2 breeding tanks, a pet shop tank, a sold tank & my 100% pet tank.

& damn did it ever take a long time to change the tanks, I pretty much changed 2 a day.

I also had a rat & mice mixed together, because my rat was getting lonely when I was at school or work