I used to have an issue with rats escaping during cleaning. I was always able to catch them, but rats are easier to catch than mice. I know you ended up getting your escaped ones from a box you set out to sell, but cleaning was always the most opportune time for them to escape. So I made an extra "rack" when cleaning so I could easily transfer them to clean tubs....so far no escapee since.

https://drive.google.com/file/d/1j1qY8Gmg3CuJmo8eo_HhiSYft_nruDow/view?usp=sharing

https://drive.google.com/file/d/1DR2...ew?usp=sharing