Last summer a big black bear jumped on into my back yard and bit my little buckling on the butt- she let him go when he screamed, guess it startled her. I chased her with a sword and threatened in not-so-nice words (gun safe was too far, this has been remedied). She got the message and left, proceeded to evade fish/game traps and bedded down in my front pasture for over a month out of spite. I finally went out with the gun looking for her one night with a friend- she got the message and left.
Bears are opportunistic and generally, lazy feeders (I'll hold the typical "like many Americans" joke... oh, whoops!). If you take in your bbq, trash bins, and don't have a bunch of sweet fruits growing all over your property, you're on the right track. Apparently a chemical in paint balls attracts bears, so don't use paint balls to redecorate if you can avoid it.
We haven't had any griz come on the property yet, thank God. When that happens, I may wake up 10 goats short... if the yaks don't get him first.