This is the mat that comes with them. They can follow that black line or you can use it as a Sumo ring if you also have Didi.
To keep these happy, you can feed and interact with them by pushing their bellybutton to get them in to various modes or they can be fed, given medicine, play and learn songs over the internet at their website.
When you chose an activity to download over the internet, you put the mouse's belly on your monitor. The box you put it on blinks in a series of black and white flashes that the infared sensor reads to complete the activity.
I have really been enjoying my little Fred. His electronic squeeks are adorable.