What do pet stores do with older hamsters that haven’t been sold?

For that matter, what do they do with older mice or rats that are no longer young enough to be cute and appealing to the kids? Do the pet stores sell them to second-hand pet shops frequented by shady mobsters who want mean untamed pets? Do the pet stores ship them overseas to be recycled? Inquiring minds want to know.

In the pet shop I worked in older unsold rodents and rabbits were fed to snakes.

Introduction to the Relocation Industry