Usually they'll go away. Black bears generally are aggressive only when you get between a mother and her cubs, San Julian says. Don't climb a tree to get away. If you climb that tree, she's not going to be happy. Bears can run up to 30 miles an hour, he adds, but when crossing a highway, they're no match for a car or truck.
Many beekeepers protect hives with electric fences.
Although bears can go through a fence, it trains them to keep out. If your hives were attacked previously, you may want to bait the fence with a half-open can of sardines. When the bear grabs the food, the fence will zap him. The point is not to do him harm, but surprise him, so he associates the food with a bad experience. Bears also have been known to walk through cornfields, lie down and damage large circular areas, San Julian says.