Hi Zoe
the main reason would be convenience in terms of cleanup. I think it also depends on whether you are displaying the snakes for the family to see or just keeping them in racks or non-display enclosures.
I use BC for all my enclosures and it is convenient when it comes to mucking out. I'm planning on switching to a woodchip woodmulch mixture shortly as I've got about ten tons of the stuff. I'm planning on building a steamer unit that I can sterilise this with. This way I hope to get a natural look and the easy cleanup too. I'll probably put a layer of BC underneath to soak up anything that might pass through it.
The beauty of the black pebbles would be that you can pull the whole lot out and easily disinfect it - just a bit more trouble but nice to look at.
Graham
