We moved to Barcelona last year and brought our bunnies with us. They live in a room in our basement which is 11’ x 10’ and has a tunnel for them to run up and get out into the garden through a small sliding window when we are at home. They tend to spend almost all of their time in the basement and don’t venture out into the garden much so I’m worried that their claws are growing too long as the basement floor is painted concrete and very smooth. Any views on what I could lay down on the floor that is more abrasive but will not damage their feet? I was thinking of putting anti slip floor tape in their tunnel to help, but also something to lay on the floor would be good too. Clearly, I don’t want anything that could harm them if they chew on it. Another idea is a sand pit for them to dig in – there’s no shortage of sand around here to replenish it with. Any ideas welcome.