against her will. Thank you. Did you know that bear season is just beginning? Hikers in and near yellowstone national park know that after two separate attacks by grizzlies in the last 24 hours.... See More
against her will. Thank you. Did you know that bear season is just beginning? Hikers in and near yellowstone national park know that after two separate attacks by grizzlies in the last 24 hours. Tonight the warnings from the experts who know these bears. Here's abc's linzie janis. Reporter: Four hikers in yellowstone national park, charged by a mother bear, protecting her cub. Two of the hikers were mauled, but all escaped alive. Just 50 miles away in idaho, another attack. This time two park workers accidentally woke a sleeping grizzly. It attacked. Both men are hospitalized tonight. It is bear season. When bears come out to bulk up before hibernation. In yosemite alone, bear encounters are up 64% from last year. But bears are also venturing closer to civilization. This furry thief stole an entire dumpster in colorado for a bear buffet. And here in hopchang, new jersey, police say they get around three calls a week from residents reporting black bears in their backyards. Georgette machitto had an unwelcome visitor on sunday. He was on that hill right there. Coming toward me. Oh, my gosh. You were in your car? I was in the car. Reporter: If you find yourself near a back, back away slowly. But if the bear keeps coming? One of the biggest myths is play dead. Don't do that. They eat dead animals. And if he gets close, just act as big as you can. Reporter: That means stand tall, wave your arms and yell. This family filmed a bear climbing out of the front seat of their truck. To check out the back. Cute to some, but also very dangerous. If a bear gets that close to your house, make a lot of noise, bang pots and pans together. If you're hiking, carry a can of this, it's bear spray, like a pepper spray or mace. It has a range of 30 feet. It's a lot better than nothing. They say don't play dead. Act as big as you can. Thanks.
This transcript has been automatically generated and may not be 100% accurate.