Lino is ok if they're not on it all the time and their nails aren't too long--long nails can make them prone to sore hocks (on any surface) and reduce the amount of foot in contact with the floor (less traction). I use washable indoor-outdoor carpet, like what some doormats are made of. At the shelter, we put an old bath towel down in the cage. This is ok unless they like to eat fabric. They're easy to clean too and great if you have an old set of towels or two, or you could get some at the Goodwill store, etc. My guys like to go on the tile floor in the kitchen to cool off their bellies and don't have a lot of problems with it in terms of traction. They don't do very well on the wood floors, so we put down as many carpets as we can.