Blom, H. J. M., Witkam, A. C. P., Schlingmann, F. et al. 1993. Demonstration of Preference for Clean Versus Soiled Cages As Expressed by Laboratory Mice. Utrecht University , Utrecht, The Netherlands.

Mice in cages with flooring consisting partly of wire mesh and partly of sawdust bedding chose the bedded area for sleeping. They kept their sleeping area clean and deposited almost all their excreta on the wire mesh. When offered a choice between a solid-floored bedded cage area and an area with a wire mesh base, they deposited urine and feces on the mesh.