Location

The code

 1   class Location
 2   {
 3     public Fox Fox;
 4     public Warren Warren;
 5  
 6     public Location()
 7     {
 8       Fox = null;
 9       Warren = null;
10     }
11   }

Explanation

A location has 2 data items within the class, a Fox called Fox and a Warren called Warren.

When the location is created both are set to null.