other!
I tried the PAH wood pellets, but when they absorb liquid they crumble and just become very messy in my opinion,
soo I swapped to 'Back to Nature' which is recycled paper pellets available from the hay experts.
I think if you have smaller buns/small number of buns, hay an newspaper is good, but I have two dwarf lops, a small mixed bun, and a french lop all using a large underbed storage box needs something to absorb the liquid!