I would think bears are smart enough and smell well enough (and we smell bad enough) that when he finds either hung food or a cannister of food, he has a pretty good idea that humans are nearby, IF the bear has had experience with backpackers. I suppose if a bear had never seen a backpacker and just found the food, he would not connect the two. Habituated bears certainly will find you too and sniff around a bit. So YOU should not smell like food! The latest FS stuff I have read says to put bear cans 300 yards from your camp. That seems like a long ways to walk to get your food in the morning, but not such a long ways in terms of bear territory.

I am not sure how you keep a bear away from you. I would think that if they are in the immediate area they will know you are there unless the wind is steadily blowing your scent away from them. I think most animals are VERY aware of our presence. They have to be accutely aware of other creatures nearby- it is a matter of survival for them. I have also noticed that birds and squirrls quickly see me when I am backpacking and make noises, which I would think other animals can "read". Whether the bear is attracted to you or fears you is likely a matter of his history with people.

I am no expert on animals, so if someone else knows better, I would be interested in hearing thier ideas.