Your friend Tracy has a ball python and a ferret as pets, and feeds them both frozen mice from the pet store.?

It is not because as someone has said because the snake is cold blooded, which is nonsense. Indeed, the snake's blood may be quite warm. It is because the snake is an endothermic animal whose body temperature is greatly affected by ambient temperature. It does not have a high metabolic rate like the ferret. The ferret is an exothermic animal which uses physiological mechanisms to maintain a constant core body temperature. Because of its high metabolic rate the ferret requires more food per body mass than the snake.

My friend Tracy doesn't have any pets.  ( : 

Because the python is coldblooded, and therefor does not waste energy on keeping its own body warm like the ferret does.

Also, ferrets like to run around, pythons often lie around for many hours