Darn deer, they know who's a threat for real and who isn't.
We passed a black vulture on the road the other day. He was on a squirrel roadkill. We cruised on by at 35 mph, he was in the marked roadway but some inches inside the line. He just checked us out and took a couple steps to the other side of the critter. THey seem quite studious about our habits and when the danger isn't real.