Or you could just get one long piece of flexwatt and weave it between the levels of the rack.

I have a Boaphile, and I know that is how it is wired, and I think that might be how Reptile Basics makes the racks too.

Either way would work...whatever you are comfortable with and what would work for you.

Also, if you have more than one thermostat, or a herpstat II or something simliar that can control more than one device you could wire the shelves in two seperate sections. Then you would have the freedom of housing different snakes with different temp requirements -- ie balls and maybe colubrids....