Midnight may not know about the practice of quarantine. =)

Generally, herpers will quarantine or house the new snake in a seperate room for generally 3 months. This quarantine period is used to verify that the new animal does not have any parasites it may spread to your already established snakes.

For example, I added a boa constrictor to my snake collection and have been quarantining her in another room away from my established ball python. Six weeks into the quarantine period, she turned out to have mites! I was able to eliminate the mites from my boa without the mites spreading to my ball python.