The ferret is a domestic mammal in the Mustelidae (weasel) family, with a life span of 7 to 10 years. Ferrets were believed to be developed from the European polecat in the middle ages and used to rid castles of rodents. They are fierce hunters and cannot be allowed near our birds or small mammals at the zoo. They spend 18 hours a day sleeping, and the remaining time in vigorous play. They are known for “stealing” small objects and hiding them away. Our Minnie and Lilly (both 5 years old) love to stash dried banana slices.