Quote Originally Posted by Cop View Post
What's the supposed to mean?
If you don't strictly adhere to quarantine standards, you risk infecting your other animals inadvertently. You should keep new animals as far from your established animals for about 3 months so you can observe the life cycle of any diseases or other issues they may have without spreading them to your other animals.

You should wash your hands thoroughly before and after handling each animal, and keep an eye out for potential problems. After that time is up, and assuming nothing has thrown up a warning flag (RI, mites, etc), it can be assumed to be safe to house the animals in the same room, take pictures together, etc.