The change in your source of feeders is likely the reason- they probably feed their rodents differently -maybe dogfood instead of professional rodent chow? That's also a good sign that it's not real stinky. Adding some Bene-Bac might help & shouldn't hurt, that's a good idea. Seeing the change from normal stools would make me reconsider the new food source, but that's me. I can totally understand about the high shipping costs.