I purchased a rat from PetCo, and she was a WONDERFUL pet.
Petco advised me to get her a cage that she COMPLETELY outgrew (the wheel in her cage ground her shoulder blades raw even though PetCo said she wouldn't get too big for it).
Additionally, she suffered nerve damage from being picked up by her tail, and came with free mites, which also gave her a bacterial infection that led to a permanent head tilt (her equilibrium was permanatley damaged). Also, she was being housed with some males...I am VERY lucky I didn't pick a pregnant rat. She died of at 1 and 1/2 years old, and PetCo said she'd live to be 6. The vets suspected it was because she had been overall very unhealthy. She was a 500$ rat by the time I was done with the vets.
I do not know if they treat their hamsters/gerbils, ferrets, etc. like they do the rats and mice, but I will NEVER buy from them again and support the cruelty they display to their feeder pets.
They breed their rats and mice to be snake food, NOT to be acceptable pets. They breed them for quantity, NOT quality! I understand snakes need to eat too, but PetCo should not give people the hopes of having a long term pet, when it is an OBVIOUS lie.