Exactly. Do rats ‘clean their plates’??
Do rats like a plate of tasty poo? It’s repeated so often, you’d think it must be true…
But you’d also think we’d see a bunch of nibbled-on orphan poos lying around, if they were so very very tasty.
Ever seen a half-nibbled poo? Me neither. But we’ll keep looking…

(c) clarkmaxwell

Then go read this post at Havealittletalk’s Blog. It’s awesome.

Man and dog are both oblivious, but these rats, with their big bellies and little feet and curly tails, are wiggling their snouts and whiskers, waiting to feast on the next pile of poop.

Ha ha ha!

I have another point to add to the answer, in addition to what was contributed by the previous answer (above). Living in a city where rats are prevalent, I did an experiment. I own a dog and clean up its feces at the end of each day. I then placed each day’s ‘collections’ in my plastic garbage can with a hole chewed in the bottom by hungry rats (garbabe can provided by landlord, and hole present years prior to my household, and long prior to our dog). The poo was inside the average thin skinned grocery store bag.

One week later, after watching many rats run through my alley, the dog poo is untouched…leading me to conclude that although as stated in the first answer, rats may eat dog feces in some situations, the presence of dog feces when there are other rodent attractants (fast food dumpsters, not secured metal garbage cans, and litter in general) probably have no effect on an existing rat problem.

As an aside, especially in urban environments, responsible owners should clean up their pet waste with regularity. However, I can conclude that dog waste is likely a last resort for hungry rats, more akin to the Donner party than a scrumptious buffet.

It would be an interesting question for anyone researching this further to see if there was some kind of control for the possibility that people who don’t clean up their pet waste may not keep open garbage or other rodent attractants out of their yards or nearby areas.