I have a selection of pets, whom i love dearly, but gosh they are expensive to keep! I give them the best of my budget but still, like all areas of my life, i like to get the best for my money. It seems that the obvious way to save some cash with multi pet owning is to find a substrate/bedding/floor covering that will suit as many animals as possible.
So heres my challenge: I need a material that will suit as many of the below as possible 
Rabbits
Piggies
Hamsters
Harvest Mice
Royal Python
Herman Tortoise
Degu
About to get:
Silkies (ideally but maybe other Bantam type chicken)
Quail
(also a cat and a dog but dont really need anything for them)
.......ready......steady......GO!