Willig vs. the dead mole

Last week, after lunging, Willig had another turn-out opportunity. He was doing pretty well - following me around but eating, and not too much staring at the barn or running around all crazy man.
But then as we were heading back on our last loop, he was in the middle eating, and then he stopped, sniffed, snorted, jumped with all four legs straight, sniffed, snorted again, and ran over to me and almost ran me over.
So I walked over to where he'd been sniffing, snorting, etc. and there was a dead mole (or something) that the lawnmower ran over.
Willig followed me over to investigate again, and repeated the whole performance.
As we walked back to the gate, he stayed right on my shoulder - like twice he stepped on my heel, and I couldn't get him away from me.
So apparently Willig is afraid of death.