That's interesting, I'd never heard it was an instinctual thing to cover their tracks. Aren't wolves predators in the wild, though? Or are they hiding the poop from their prey? Doesn't it have to come out some time?
That would explain why most dogs want to run away from it as soon as they're done, though. Thor hates waiting for me to get the little baggy out. "Mom, we have to leave! I POOPED!"

Or when they try to kick dirt over it.
I have heard that once developed, this is an extremely difficult habit to break. There are a couple other possibilities:
- your dog eats her food too fast, and is not digesting it properly. Protein in the poop = yummy. That's why pineapple is supposed to help, the enzymes in the pineapple are supposed to break down the proteins.
- for whatever reason, perhaps a low quality food, the dog can still smell that delicious protein in her poop. Honestly, I would expect in these cases that a LOWER protein food would help, but I can see why some fillers like corn might cause it to pass through the gut more quickly, leaving it undigested.
- You can sprinkle hot sauce on it before they get there. I think a lot of dogs can smell the hot sauce, so they figure out when it's safe to eat, but I've heard this can help.
- You can pick it up right away so they don't have a chance.
- I'm sure with some work, you could train them to leave it when they are alone. You could probably teach them that a big old log when you come back means a HUGE treat, something they don't want to miss! And maybe that would motivate them to let it be.