I don't know about looking up. But they can tell the difference in a hunters 4 wheeler and a kid running up the ridges.

I was hunting last weekend and had a group of does out in my food plot. There was someone racing up and down the road on a 4 wheeler a couple hundred yards away. They paid it no attention. Then right at dark I heard another 4 wheeler start up on the farm behind me. I guess a hunter was leaving his stand. When that 4 wheeler started putting down the trail slowly,all 4 does went on alert and threw their tails up and left the plot in a hurry. I think they knew the difference in the sounds of thetwo 4 wheelers. The one racing was no danger to them. But the slow moving one set off their alarms.

THEY MOST CERTAINLY DO LEARN!!!