hey there, this might be a bit of a niche question, but I was wondering if gravel or sand can be used as a more "natural" mouse substrate for fancy/pet mice. At various zoos and around the internet I've seen sand and gravel used for zebra mice or harvest mice - but wondering if the same can be done for pets. I'd quite like to get a naturalistic set up going (side note - is a mouse house or tank outside or in a greenhouse okay?) but the substrate has been the most difficult bit to sort out! I've tried soil before but it tends to dry out and get a bit dusty which is a recipe for respiratory infections. hopefully these links work (my first post so sorry for formatting!), but this is kind of the look I'm going for. Enclosure Harvest mice - ZooChat Spiny mouse enclosure - ZooChat New Barbary striped grass mouse enclosure - ZooChat Cretan Spiny Mouse Enclosure at Krefeld, 15/06/19 - ZooChat thanks!