I tried pine shavings but they seem to try to eat it, I'm back to straw now, they seem to scramble around on it fairly well, though it takes more effort to climb in the straw, they don't confuse it with the pine bark/shavings, I don't use alfalfa at all - it's dusty, it molds quickly and it's not all that good for them to eat, I've read it can cause problems eating too much of it, just plain ole straw.