Due to new additions and my females taking their dear sweet time getting pregnant again, I ran into a few weeks where no feeders were ready for snakes. My roommate grabbed a few "gourmet" frozen small rats from Petco. We thawed them in the bags and then dumped them into hot water and were immediately horrified. The water turned cloudy brown/red, fur was coming off in chunks, and the smell was like rotting fish. The rats looked thin, contorted, and sickly. Both packages looked like this and we immediately tossed them!
I decided not to test the rest of their stock and got live small rats from a trusted source. After witnessing what slimed out of those bags I'll never by frozen feeders again!