I have bought two bags of bird food and one bag of dog food. Both were infested; I WAS FURIOUS that I fed that to the bird! The dogs are hardy, but the cockatoo... GRRRRR!!!!
I've been using a small, indie feed store since; not quite as convenient, but very clean.
If 'yall have pets and a PetsMart, be VERY careful. Also, my job has provided me with 'insider info' that PetCo has the same problem, but worse.