Bears are wild animals. They want *food*. In most cases, avoid feeding them parts of yourself.
Yes, sometimes, as Bob mentioned, they are focused on a better food supply than what you represent. Most of the time, this is the case. Your food is what they are after. Bear bagging (hanging in a tree that they cannot climb or reach) is pretty safe. They don't care too much for people, generally. Encroaching on their teritority is not good. They will attack. Don't go near a cub. Getting out of cooking cloths and hanging them makes sense in Grizzly country. I have had a few black bears through camp checking out stuff. Indeed, my old shoes were chewed one night. I must have spilled something on one of them. Yes, their smell is reportedly 7 times stronger than a dogs. They *can* tell if it is real food or just the smell of food. They can *smell* how much and pretty well locate it in total darkness. They can tell if it is alive, like you, or, dead...like your food.
Usually, a little care, and a few precautions are all that is needed. Use your smarts. The bear thinks about food and mating 90% of his time. Study up on his habits in your area. Outsmart him.
As far as 3/4 length pads go, I often kick up a pile of forest duff to lay my pad on, so I just ignore it. In cold weather, I put my pack under my feet and legs.