Scratch marks in a fire pit, garbage at the site, or nearby scat mean the area's bruins might have learned to associate campers with food. Avoid problem bears by pitching your tent elsewhere.
In late summer and early fall, bears are out gorging on berries and nuts during the day. Avoid surprising them by clapping or singing near dense thickets, especially if you're downwind.
Runny, hairy, and smelly droppings indicate a bear is eating meat, which might mean a carcass (which a bear would defend) lies nearby. Leave the area.