I know that chickens sometimes develop the egg-eating habit, but do ducks also? I've had a nice egg from one of my runner ducks every morning for the last five mornings, and then this morning there was just a pile of yolk, and a soft shell off to the side. I did find one soft-shelled egg yesterday too, although the rest have been normal. I don't know if this one just got trampled on or if they intentionally destroyed it in the pen before I let them out. I don't want them to start eating eggs!