the hardest thing i had to do was get mice that wouldnt eat thier babies, after that it was a breeze. i cheated as i went to walmart and got 72 quart totes with locking lids and brought them home and went to drilling air holes all in them. i drilled one big enough to stick the water bottle thru. i didnt drill them real low as to give the mice something to start chewing on. i got rodent block and made a closing basket out of hardware cloth and hung it up in the enclosure and keep them some hamster food in a dish also. usually with mine at least so far, it doesnt matter which female has them they all seem to take care fo the babies. also built one for my pair of rats and it is working good for them also just had to make the air holes bigger so condensation doesnt collect in it. it may not work for everyone but is working good for me now. i will say it took forever to get ones that wouldnt eat thier young. and now am keeping females raised by them. hope this helps someone. take care all