Put it this way: Keeping multiple snakes in one enclosure properly is like keeping a cobra; it's for the experts only because there are consequences for messing up. Professional zoos pull it off because they provide both large and cluttered enclosures to give plenty of separation for the animals while providing them a comfortable living environment. In addition, they have to put in a naturalistic set up simply for the viewing pleasures of their visitors. All this is a lot of extra expensive and hard work, most of which Average Joe pet keeper does not want to - or can not - invest in.