Let's take a moment to think about the activities that rats enjoy in their natural habitat. Domestic fancy rats, specifically the Rattus norvegicus species, are known to dig complex burrows, climb buildings and trees, and travel long distances in search of food. So it's essential to set up their cage in a way that mimics these natural behaviors. Creating a space that allows them to dig, climb, forage, and run will give them the mental and physical stimulation they need to thrive.