realize that although they can eat them, it is not the best option for them. Pinkies if fed to often, even as a treat can lead to fatty liver disease. They also house alot of parasites, even when they were frozen. Best wya to rid of them is to boil them, but that still yet doesnt kill off all of the worms they can house.
In the wild yes they may eat them. But the major difference is there are periods of time with little food. So the extra fat storage from eatting the occasionaly mammal can be used durring this time of little food options. In captivity we dont offer them the time of little food, instead we house them in glass boxs and offer them all the food they would need. The need to hunt is not there, the periods of time with little food is not there. So the need for this food source really isnt needed.