I took the old mousey girls out during their cage cleaning and let them run around in their adventure balls. They love it. You would think at their age they would rather just sit, eat and sleep. But these two old mice ran all over the floors, even seeming to want to run circles around my feet.
After the cleaning was complete I reconfigured the cage and tubes, adding a junction to where the mouse's favorite nest area was. Poor old Curly, 'the chubby brown mouse,' had a hard time finding the nest while her sibling ran right into it. After watching Curly searching and seeming to become more panicked I picked her up and placed her in the nest. She sniffed around, chewed on some bedding and then started mapping her paths into the nest.