Saving lives, comforting strangers, battling bears: Do dogs have instincts to help human beings? These four pets do.

Eric Nyquist for Reader's DigestThese days, you’d be hard-pressed to find a scientist who doesn’t acknowledge that most animals have the ability to feel emotion in some way. In the past decade, a tremendous amount of research has focused on how animals think and feel and the possibility that they possess reason and morals. We may never know what motivates animals when they go out of their way to save people, as they do in these stories, but in these moments, it’s hard not to see striking evidence of empathy, love, and perhaps a basic understanding of life.

Roselle’s Finest Hour

Breed: Labrador retriever

Where: New York City

On the morning of September 11, 2001, computer sales manager Michael Hingson, who is blind, went early to his office on the 78th floor of the North Tower of the World Trade Center to prepare for a meeting. As Michael worked, his guide dog, a Labrador retriever named Roselle, dozed by his feet.

At 8:46 a.m., a tremendous boom rocked the building, eliciting screams throughout the floor. Michael grabbed Roselle’s harness, trusting that the dog would lead him out of danger, and they navigated their way to a stairwell.

“Forward,” Michael instructed, and they descended the first of 1,463 steps to the lobby. After about ten floors, the stairwell grew crowded and hot, and the fumes from jet fuel had made it hard to breathe.

When a woman became hysterical, yelling that they wouldn’t make it, Roselle nudged the woman until she finally petted the dog, calmed herself, and kept walking down the stairs.

Around the 30th floor, firefighters started passing Michael on their way up. Each one stopped to offer him assistance. He declined but let Roselle be petted, providing many of the firefighters with what would be their last experience of unconditional love.

After about 45 minutes, Michael and Roselle reached the lobby, and 15 minutes later, they emerged outside to a scene of chaos. Suddenly the police yelled for everyone to run as the South Tower began to collapse.

Michael kept a tight grip on Roselle’s harness, using voice and hand commands, as they ran to a street opposite the crumbling tower. The street bounced like a trampoline, the sky rained debris, and “a deafening roar” like a hellish freight train filled the air. Hours later, Michael and Roselle made it home safely.

In the months that followed, Michael became a spokesperson for Guide Dogs for the Blind, the organization that had trained Roselle. Together, they spread their message about trust and teamwork.

In 2004, Roselle developed a blood disorder, and she retired from guiding and touring three years later. She died in 2011.

“I’ve had many other dogs,” Michael wrote, “but there is only one Roselle.”

Eric Nyquist for Reader's Digest

Little Joe Versus the Black Bear

Breed: Yorkshire terrier

Where: Ringwood, New Jersey

Deborah Epstein’s Yorkie, Joe, proved that guard dogs sometimes come in small packages. On a warm July day in 2013, Joe and his owner were lounging on Deborah’s front porch when the phone rang. Deborah stepped inside to answer it, leaving the front door open. Seconds later, Joe began barking excitedly. That’s not unusual for a terrier, especially this little shelter dog, but he “sounded a little more furious than usual,” Deborah said.

She turned around to see a 100-pound black bear making its way toward Joe’s food bowl in the living room. Big mistake. “You don’t touch [Joe’s food],” said Deborah. She watched in awe as the six-pound dog growled, barked, lunged, and nipped at the bear until it retreated. “Joe chased it right back out the door,” Deborah said. The bear escaped into the woods behind Deborah’s house.

The prospect of losing his food may have propelled Joe into action, but he managed to defend his territory and protect his owner at the same time.

“I saved him from the pound, and he saved me from a bear,” Deborah said. “We’re even.”

Eric Nyquist for Reader's Digest

Shana’s Frozen Dig

Breed: German shepherd–wolf mix

Where: Alden, New York

In 1999, Eve and Norman Fertig, founders of the Enchanted Forest Wildlife Sanctuary, saved a two-week-old half-wolf, half–German shepherd from a puppy mill. The pup they named Shana grew to an intimidating 160 pounds, but Eve said the dog trailed her like “a little lamb.”

One October several years back, as the Fertigs, both then 81, fed injured rescue animals housed in one of the buildings on their land, an unseasonable, violent snowstorm blew in. When the couple went outside to check the weather, several trees fell, trapping them in a narrow alley between two buildings. Eve and Norman weren’t wearing coats or gloves and couldn’t climb over or duck below the tree trunks. For the next two and a half hours, they huddled together for warmth as the snow piled higher.

“We were in big trouble,” Eve said. “I told Norman, ‘We can’t stay here. We’ll die.'”

Around 9:30 p.m., Shana, who was outside, began burrowing toward Eve and Norman in the deep snow. It took the dog nearly two hours, but eventually she cleared a narrow tunnel about 20 feet long stretching from the front porch of the main house to the Fertigs’ location.

When Shana finally broke through the snow and reached the curled-up couple, she gave one short bark. Her message was clear: Follow me.

Norman looked at the tunnel, which was a foot high, and refused, telling Eve he’d spent too much time in foxholes in Okinawa during World War II. But in her no-nonsense Bronx accent, Eve changed her husband’s mind: “Norman, if you do not follow me, I will get a divorce.”

Shana grabbed Eve’s jacket and guided the 86-pound woman onto her back. Norman clutched Eve’s ankles, and for the next two hours, Shana pulled the couple through the tunnel.

Shana finally reached the house around 2 a.m., and the Fertigs managed to get just inside the front door. They collapsed with fatigue. The storm had knocked out the electricity and heat, but Shana lay next to them all night. “She kept us alive,” Eve said.

Firefighters arrived later that morning and were astonished at the sight. Eve said, “They kept looking at that tunnel and saying, ‘We’ve never seen anything like it.'”

After the ordeal, it took five months for Shana’s feet to heal from the injuries she received while digging.

Eric Nyquist for Reader's Digest

Max’s Painful Choice

Breed: German shepherd

Where: Novato, California

Late one night in February 2014, Jack Farell, 80, called 911 to report a dog attack. He had woken up bleeding on his kitchen floor, his left arm in the jaws of his adopted German shepherd, Max. “I thought he had turned on me,” said Jack, a retired firefighter.

But as emergency personnel figured out later, Max had actually saved Jack from carbon monoxide poisoning.

When Jack had gotten out of bed during the night, he’d passed out from inhaling the gas and collapsed to the floor. Max likely tried to wake the man by clawing his face, to no avail. So the dog took Jack’s left arm in his mouth and pulled the comatose man from the bedroom and down the hall, presumably intending to drag Jack out of the house.

When Jack learned the truth, his heart flooded with gratitude. “He saved my life,” Jack said.