Bears often display warning behaviors before charging, but these signs can be misinterpreted. Bears may yawn, clack their teeth, pound their front paws on the ground, huff, or swat the ground while showing signs of stress, such as flattened ears and a lowered head. These behaviors are intended to communicate that the bear feels threatened and may be preparing to charge. A bear may also exhibit a "bluff charge," which involves a full-tilt run toward a person but stopping short or veering off at the last moment, often with its head and ears up and forward, and may vocalize loudly. However, not all charges are bluff charges—some are genuine attacks, and it can be difficult to distinguish between the two in real time. The U.S. National Park Service emphasizes that a charge is a serious threat and should not be underestimated, as it is impossible to know whether the bear will stop before making contact. Therefore, while warning signs are common, they do not guarantee the bear will not attack.