If you have other pet rodents or Lagomorphs (Rabbits) at home you must quarantine your new mice before bringing them into the same air space as your other animals. Even though we health test our animals, the conditions at every breeder's facility are different even if they also health test their animals. The stress of being transported and of settling into a new home can cause mice to present illnesses that they would not have developed if they would not otherwise have shown. Therefore for the safety of your new pet mice and also for any other small animals you may have in the house, you must quarantine your new mice for a minimum of 4 weeks.
Separate new animals into a different air space. This can be as simple as keeping your mice inside if you have rabbits outside, or it could entail keeping new animals temporarily in your garage or in a closed room at the other end of the house from you other animals.
Care for the new animals last so that you do not carry bacteria or viruses on your hands or tools between enclosures.
Sanitize your tools between the old enclosures and the new ones.
If you do not have other small animals in your home then it is fine to move your mice into their new home straight away. Please let your new pets settle in and learn where their food, water, and new place to sleep will be before picking them up for handling sessions. Give them three to four days to explore and scent mark everything so they feel comfortable in their new home. You will still be giving them fresh food and water every day, and if you sprinkle in a few treats at feeding time you will very likely be able to see all of your mice for wellness checks.