A NEEDED PRECAUTION !!
So, let's say you have 1 snake, and just bought another, to keep it company. You might like to add it right away, but that's very dangerous to do. If the snake has a suspended illness, it might be opened up by the stress of the moving, and infect the latter you already have with the germs he or she has... That's why I put my new snakes into a separated quarantine tank. The tank is in a separated room, from the other snakes, so contamination is limited to me, and my P.H. !!! The new snake will stay there at least 4 weeks, in a bare cage, with a paper as floor, a hiding place and a bowl o water, befor I can safely say it's ok to move to a fully functional cage.... In my case she ( Sunshine ) stays in the tank, until she's about 1 meter ( 3 feet ) so I can safely introduce her to Melanie, witch will be than about 2.3 meters.