Just my thoughts on newspaper. All newspapers are bleached white using chlorine. When the snakes urea mixes with this a toxic gas is the result. I would guess frequent changing avoids this, but if you're away for a few weeks the buildup can affect your snakes, especially babies. There are alternative papers to use where chlorine is not used: Paper towels, napkins sold in health stores, whole food markets, etc., where no bleaching of any kind is used.
Mike




