I'm not sure if it was just feces, or other fluids that were coming out, and I do understand that you are going to get a few "turds" mixed in with your frozen rats. But compared to the batch of small rats that I bought from them at the same time -- there was a significant difference.
And, it wasn't that there was some fecal matter in the same package as them, there was literally feces matted into their hair, like the had been living in it (or spent some time dead in it) for quite some time.
Later,
George
BTW -- I just received the replacement shipment yesterday, and the rats are perfect!