sorry I'm multitasking and I suck at spelling.
yes, they are sagregated by size in different size enclosures. As far as refreezing mice I do not think it is a good idea since freezing doe not kill the bacteria and microbes which multyply in great numbers after the mouse /rat has been thawed. Remeber frozen mice/rats still contain their gutts which are full of bacteria. Fortunately I have my other snake , which is always eager for extra food so no mice get wasted .LOL