On Saturday I bought a large bag of Pro-Plan Large Breed Puppy at PetSmart. When I got it home I poured it into the bin I use to store food. At the very end of emptying the bag several clumps of kibble came out with some sort of contaminate holding them together, I'm not sure what it was but it kind of looked like fur. Upon closer inspection there were also several winged insects mixed in. I took put the impacted portions in a plastic bag and went back to PetSmart and they gave me a new bag immediately, I tossed the rest of what was in the impacted bag.
If I was feeding straight from the bag and not transferring the full bag to a storage container I never would have known until the end. Just and FYI for anyone feeding it to maybe take a closer look.
It might have been totally harmless but I certainly didn't want to take a chance.